diff --git a/studio/backend/core/training/trainer.py b/studio/backend/core/training/trainer.py
index 26720865f4..8e419849cb 100644
--- a/studio/backend/core/training/trainer.py
+++ b/studio/backend/core/training/trainer.py
@@ -3425,15 +3425,19 @@ class UnslothTrainer:
                     logger.info(
                         f"CPT: using UnslothTrainer with embedding_learning_rate={embedding_lr}\n"
                     )
+                    cpt_args = _UnslothTrainingArguments(
+                        embedding_learning_rate = embedding_lr,
+                        **config_args,
+                    )
+                    if config_args.get("packing", False):
+                        cpt_args.packing_strategy = "wrapped"
+                        logger.info("CPT packing strategy: wrapped\n")
                     trainer_kwargs = {
                         "model": self.model,
                         "tokenizer": sft_tokenizer,
                         "train_dataset": dataset["dataset"],
                         "data_collator": data_collator,
-                        "args": _UnslothTrainingArguments(
-                            embedding_learning_rate = embedding_lr,
-                            **config_args,
-                        ),
+                        "args": cpt_args,
                     }
                     if eval_dataset is not None:
                         trainer_kwargs["eval_dataset"] = eval_dataset
diff --git a/tests/utils/test_packing.py b/tests/utils/test_packing.py
index a8557d8533..98c29d9f0f 100644
--- a/tests/utils/test_packing.py
+++ b/tests/utils/test_packing.py
@@ -14,6 +14,7 @@
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 from unsloth import FastLanguageModel
+import unsloth.trainer as trainer_module
 from unsloth.utils import attention_dispatch as attention_dispatch_utils
 from unsloth.utils.packing import (
     configure_padding_free,
@@ -29,7 +30,7 @@ from unittest.mock import patch
 
 import pytest
 import torch
-from datasets import Dataset
+from datasets import Dataset, IterableDataset
 from trl import SFTConfig, SFTTrainer
 from trl.trainer.sft_trainer import DataCollatorForLanguageModeling
 
@@ -160,6 +161,374 @@ def test_configure_padding_free():
     assert config.remove_unused_columns is False
 
 
+def _patch_fake_sft_trainer():
+    class FakeSFTTrainer:
+        def __init__(self, *args, **kwargs):
+            self.model = args[0] if len(args) >= 1 else kwargs["model"]
+            self.args = args[1] if len(args) >= 2 else kwargs["args"]
+            self.data_collator = args[2] if len(args) >= 3 else kwargs.get("data_collator")
+
+    trainer_module._patch_sft_trainer_auto_packing(SimpleNamespace(SFTTrainer = FakeSFTTrainer))
+    return FakeSFTTrainer
+
+
+def _vlm_model():
+    return SimpleNamespace(
+        config = SimpleNamespace(
+            architectures = ["Gemma4ForConditionalGeneration"],
+            model_type = "gemma4",
+            vision_config = SimpleNamespace(),
+        ),
+        max_seq_length = 16,
+    )
+
+
+def _text_model():
+    return SimpleNamespace(
+        config = SimpleNamespace(
+            architectures = ["LlamaForCausalLM"],
+            model_type = "llama",
+        ),
+        max_seq_length = 16,
+    )
+
+
+class _CharacterTokenizer:
+    bos_token = None
+    eos_token = None
+    chat_template = None
+
+    def __call__(self, texts, **kwargs):
+        is_batched = isinstance(texts, list)
+        if not is_batched:
+            texts = [texts]
+        input_ids = [[ord(char) for char in text] for text in texts]
+        if kwargs.get("truncation") and kwargs.get("max_length") is not None:
+            input_ids = [ids[: kwargs["max_length"]] for ids in input_ids]
+        return {"input_ids": input_ids if is_batched else input_ids[0]}
+
+
+def test_vlm_text_dataset_allows_explicit_packing():
+    fake_trainer = _patch_fake_sft_trainer()
+    config = SimpleNamespace(packing = True, padding_free = None, remove_unused_columns = True)
+
+    trainer = fake_trainer(
+        model = _vlm_model(),
+        args = config,
+        processing_class = object(),
+        train_dataset = Dataset.from_dict({"text": ["text-only CPT sample"]}),
+    )
+
+    assert config.packing is True
+    assert config.padding_free is True
+    assert trainer.model._unsloth_allow_packed_overlength is True
+
+
+def test_vlm_without_processing_class_still_disables_packing():
+    fake_trainer = _patch_fake_sft_trainer()
+    config = SimpleNamespace(packing = True, padding_free = None, remove_unused_columns = True)
+
+    fake_trainer(
+        _vlm_model(),
+        config,
+        None,
+        Dataset.from_dict({"text": ["text-only sample"]}),
+    )
+
+    assert config.packing is False
+    assert config.padding_free is False
+
+
+@pytest.mark.parametrize(
+    ("model_type", "architecture"),
+    (
+        ("t5", "T5ForConditionalGeneration"),
+        ("bart", "BartForConditionalGeneration"),
+        ("whisper", "WhisperForConditionalGeneration"),
+        ("csm", "CsmForConditionalGeneration"),
+    ),
+)
+def test_nonvision_conditional_generation_keeps_packing(model_type, architecture):
+    fake_trainer = _patch_fake_sft_trainer()
+    config = SimpleNamespace(packing = True, padding_free = None, remove_unused_columns = True)
+    model = SimpleNamespace(
+        config = SimpleNamespace(model_type = model_type, architectures = [architecture]),
+        max_seq_length = 16,
+    )
+
+    trainer = fake_trainer(
+        model,
+        config,
+        None,
+        Dataset.from_dict({"text": ["text-only sample"]}),
+    )
+
+    assert config.packing is True
+    assert config.padding_free is True
+    assert trainer.model._unsloth_allow_packed_overlength is True
+
+
+def test_vlm_vision_dataset_still_disables_packing():
+    fake_trainer = _patch_fake_sft_trainer()
+    config = SimpleNamespace(packing = True, padding_free = None, remove_unused_columns = True)
+
+    fake_trainer(
+        _vlm_model(),
+        config,
+        None,
+        Dataset.from_dict({"images": [None], "text": ["multimodal sample"]}),
+        None,
+        object(),
+    )
+
+    assert config.packing is False
+    assert config.padding_free is False
+
+
+@pytest.mark.parametrize(
+    "vision_column",
+    ("pixel_values", "pixel_attention_mask", "image_grid_thw"),
+)
+def test_vlm_preprocessed_vision_dataset_disables_packing(vision_column):
+    fake_trainer = _patch_fake_sft_trainer()
+    config = SimpleNamespace(packing = True, padding_free = None, remove_unused_columns = True)
+
+    fake_trainer(
+        model = _vlm_model(),
+        args = config,
+        processing_class = object(),
+        train_dataset = Dataset.from_dict({"input_ids": [[1]], vision_column: [None]}),
+    )
+
+    assert config.packing is False
+    assert config.padding_free is False
+
+
+@pytest.mark.parametrize("dict_eval", (False, True))
+def test_vlm_vision_eval_dataset_disables_packing(dict_eval):
+    fake_trainer = _patch_fake_sft_trainer()
+    config = SimpleNamespace(packing = True, padding_free = None, remove_unused_columns = True)
+    eval_dataset = Dataset.from_dict({"input_ids": [[1]], "pixel_values": [None]})
+    if dict_eval:
+        eval_dataset = {"vision": eval_dataset}
+
+    fake_trainer(
+        model = _vlm_model(),
+        args = config,
+        processing_class = object(),
+        train_dataset = Dataset.from_dict({"text": ["text-only training sample"]}),
+        eval_dataset = eval_dataset,
+    )
+
+    assert config.packing is False
+    assert config.padding_free is False
+
+
+def test_vlm_streaming_vision_dataset_without_metadata_disables_packing():
+    fake_trainer = _patch_fake_sft_trainer()
+    config = SimpleNamespace(packing = True, padding_free = None, remove_unused_columns = True)
+    dataset = IterableDataset.from_generator(
+        lambda: iter([{"images": [None], "text": "multimodal sample"}])
+    )
+    assert dataset.column_names is None
+
+    fake_trainer(
+        model = _vlm_model(),
+        args = config,
+        processing_class = object(),
+        train_dataset = dataset,
+    )
+
+    assert config.packing is False
+    assert config.padding_free is False
+    assert next(iter(dataset))["text"] == "multimodal sample"
+
+
+@pytest.mark.parametrize("data_collator", (None, object()))
+def test_stateful_stream_is_not_consumed_during_detection(data_collator):
+    class StatefulDataset:
+        def __init__(self):
+            self.rows = iter([{"text": "first"}, {"text": "second"}])
+
+        def __iter__(self):
+            return (row for row in self.rows)
+
+    fake_trainer = _patch_fake_sft_trainer()
+    config = SimpleNamespace(packing = True, padding_free = None, remove_unused_columns = True)
+    dataset = StatefulDataset()
+
+    fake_trainer(
+        model = _vlm_model(),
+        args = config,
+        processing_class = object(),
+        data_collator = data_collator,
+        train_dataset = dataset,
+    )
+
+    assert config.packing is False
+    assert config.padding_free is False
+    assert next(iter(dataset))["text"] == "first"
+
+
+def test_text_model_stream_without_metadata_keeps_packing():
+    class StatefulDataset:
+        def __init__(self):
+            self.rows = iter([{"text": "first"}, {"text": "second"}])
+
+        def __iter__(self):
+            return (row for row in self.rows)
+
+    fake_trainer = _patch_fake_sft_trainer()
+    config = SimpleNamespace(packing = True, padding_free = None, remove_unused_columns = True)
+    dataset = StatefulDataset()
+
+    trainer = fake_trainer(
+        model = _text_model(),
+        args = config,
+        processing_class = object(),
+        train_dataset = dataset,
+    )
+
+    assert config.packing is True
+    assert config.padding_free is True
+    assert trainer.model._unsloth_allow_packed_overlength is True
+    assert next(iter(dataset))["text"] == "first"
+
+
+def test_bfd_packing_truncates_before_packing(monkeypatch):
+    args = SimpleNamespace(
+        dataset_num_proc = 1,
+        dataset_text_field = "text",
+        max_length = 4,
+        packing_strategy = "bfd",
+    )
+    trainer = SimpleNamespace(model = None)
+    dataset = Dataset.from_dict({"prompt": ["abc"], "completion": ["defghij"]})
+    prepare_globals = SFTTrainer._prepare_dataset.__globals__
+
+    def passthrough_pack_dataset(dataset, seq_length, strategy, map_kwargs):
+        return dataset
+
+    monkeypatch.setitem(prepare_globals, "pack_dataset", passthrough_pack_dataset)
+    packed = SFTTrainer._prepare_dataset(
+        trainer,
+        dataset,
+        _CharacterTokenizer(),
+        args,
+        True,
+        None,
+        "train",
+    )
+
+    assert len(packed["input_ids"][0]) == args.max_length
+
+
+def test_wrapped_strategy_without_packing_still_truncates():
+    args = SimpleNamespace(
+        dataset_num_proc = 1,
+        dataset_text_field = "text",
+        max_length = 4,
+        packing_strategy = "wrapped",
+    )
+    trainer = SimpleNamespace(model = None)
+    dataset = Dataset.from_dict({"text": ["abcdefghi"]})
+
+    prepared = SFTTrainer._prepare_dataset(
+        trainer,
+        dataset,
+        _CharacterTokenizer(),
+        args,
+        False,
+        None,
+        "train",
+    )
+
+    assert len(prepared["input_ids"][0]) == args.max_length
+
+
+@pytest.mark.parametrize("legacy_api", (False, True))
+def test_wrapped_packing_preserves_overlength_tokens(monkeypatch, legacy_api):
+    args_kwargs = {
+        "dataset_num_proc": 1,
+        "dataset_text_field": "text",
+        "max_length": 4,
+    }
+    if not legacy_api:
+        args_kwargs["packing_strategy"] = "wrapped"
+    args = SimpleNamespace(**args_kwargs)
+    trainer = SimpleNamespace(model = None)
+    dataset = Dataset.from_dict({"text": ["abcdefghi"]})
+    prepare_globals = SFTTrainer._prepare_dataset.__globals__
+    pack_dataset = prepare_globals["pack_dataset"]
+
+    def legacy_pack_dataset(
+        dataset,
+        seq_length,
+        map_kwargs = None,
+    ):
+        return pack_dataset(dataset, seq_length, "wrapped", map_kwargs)
+
+    if legacy_api:
+        monkeypatch.setitem(prepare_globals, "pack_dataset", legacy_pack_dataset)
+
+    packed = SFTTrainer._prepare_dataset(
+        trainer,
+        dataset,
+        _CharacterTokenizer(),
+        args,
+        True,
+        None,
+        "train",
+    )
+
+    packed_ids = packed["input_ids"]
+    assert sum(len(input_ids) for input_ids in packed_ids) == 9
+    assert all(len(input_ids) <= args.max_length for input_ids in packed_ids)
+
+
+# Named to match the unsloth_zoo helper: sft_trainer_prepare_dataset sources it by
+# name and renames "def sft_prepare_dataset" -> "def _prepare_dataset". This fixture
+# deliberately omits the "All Unsloth Zoo code licensed under LGPLv3" header to emulate
+# a newer, compatible Zoo whose header moved (the dependency is only lower-bounded).
+def sft_prepare_dataset(
+    self, dataset, processing_class, args, packing, formatting_func, dataset_text_field
+):
+    do_truncation = True
+    # Mirror the Zoo call so the "truncation = do_truncation," injection anchor
+    # survives formatting (a bare tuple assignment gets rewritten to a paren form).
+    dataset = processing_class(
+        dataset,
+        truncation = do_truncation,
+    )
+    return dataset
+
+
+def test_wrapped_packing_setup_survives_missing_zoo_header(monkeypatch):
+    # Regression: the wrapped-packing setup used to anchor on the Zoo license comment,
+    # so a header change made it a no-op while the truncation reference still landed,
+    # NameError-ing every SFT dataset preparation. It must now install via the
+    # signature and always precede the reference.
+    import ast
+    import textwrap
+    import unsloth.models.rl_replacements as rlr
+
+    monkeypatch.setitem(rlr.RL_REPLACEMENTS, "sft_prepare_dataset", sft_prepare_dataset)
+
+    source = (
+        "def _prepare_dataset(self, dataset, processing_class, args, packing, "
+        "formatting_func, dataset_text_field):\n    return dataset\n"
+    )
+    patched = rlr.sft_trainer_prepare_dataset("_prepare_dataset", source)
+
+    assert "_unsloth_wrapped_packing = packing" in patched
+    assert "import inspect as _inspect" in patched
+    assert "not _unsloth_wrapped_packing" in patched
+    assert patched.index("_unsloth_wrapped_packing = packing") < patched.index(
+        "truncation = do_truncation and not _unsloth_wrapped_packing"
+    )
+    ast.parse(textwrap.dedent(patched))
+
+
 class _DummyChild(torch.nn.Module):
     def __init__(self):
         super().__init__()
diff --git a/unsloth/models/rl_replacements.py b/unsloth/models/rl_replacements.py
index ffb845b04f..b0709f7376 100644
--- a/unsloth/models/rl_replacements.py
+++ b/unsloth/models/rl_replacements.py
@@ -276,17 +276,13 @@ def dpo_trainer_vision_signature_columns(function_name, function):
     _extra_columns = "".join(f'                "{_k}",\n' for _k in _DPO_VISION_KEYS)
     new_function = function.replace(
         '                "image_sizes",\n                "token_type_ids",\n',
-        f'                "image_sizes",\n'
-        f"{_extra_columns}"
-        f'                "token_type_ids",\n',
+        f'                "image_sizes",\n{_extra_columns}                "token_type_ids",\n',
     )
     if new_function != function:
         return new_function
     return function.replace(
         '                "image_sizes",\n                "ref_chosen_logps",\n',
-        f'                "image_sizes",\n'
-        f"{_extra_columns}"
-        f'                "ref_chosen_logps",\n',
+        f'                "image_sizes",\n{_extra_columns}                "ref_chosen_logps",\n',
     )
 
 
@@ -458,6 +454,60 @@ def sft_trainer_prepare_dataset(function_name, function):
         if matched:
             # Use fast version!
             function = inspect.getsource(fast_sft_prepare_dataset)
+            # why: install the wrapped-packing setup (and the `_inspect` import the
+            # truncation / pack_dataset rewrites below depend on) at the function
+            # signature, a structural anchor that always exists, rather than the
+            # unsloth_zoo license-comment line. That header is only lower-bounded, so a
+            # newer Zoo may move or drop it; anchoring there let the setup silently
+            # no-op while the references still landed, NameError-ing every SFT dataset
+            # preparation. Fail loudly if even the signature cannot be located.
+            _wrapped_packing_setup = (
+                "    import inspect as _inspect\n"
+                "    try:\n"
+                '        _unsloth_pack_has_strategy = "strategy" in _inspect.signature(pack_dataset).parameters\n'
+                "    except Exception:\n"
+                "        _unsloth_pack_has_strategy = True\n"
+                "    _unsloth_wrapped_packing = packing and (\n"
+                '        getattr(args, "packing_strategy", None) == "wrapped"\n'
+                "        or not _unsloth_pack_has_strategy\n"
+                "    )\n"
+            )
+            function, _n_setup = re.subn(
+                r"(def sft_prepare_dataset\s*\(.*?\)\s*(?:->[^:\n]*)?:[ \t]*\n)",
+                lambda match: match.group(1) + _wrapped_packing_setup,
+                function,
+                count = 1,
+                flags = re.DOTALL,
+            )
+            if _n_setup != 1:
+                raise RuntimeError(
+                    "Unsloth: failed to install wrapped-packing support into "
+                    "sft_prepare_dataset (signature not found); please file a bug report."
+                )
+            function = function.replace(
+                "truncation = do_truncation,",
+                "truncation = do_truncation and not _unsloth_wrapped_packing,",
+            )
+            function = function.replace(
+                "if do_truncation and max_seq_length > 0:",
+                "if do_truncation and not _unsloth_wrapped_packing and max_seq_length > 0:",
+            )
+            function = function.replace(
+                """dataset = pack_dataset(
+            dataset.select_columns(used_column_names),
+            max_seq_length,
+            getattr(args, "packing_strategy", "bfd"),
+            map_kwargs,
+        )""",
+                """_pack_kwargs = {"map_kwargs": map_kwargs}
+        if "strategy" in _inspect.signature(pack_dataset).parameters:
+            _pack_kwargs["strategy"] = getattr(args, "packing_strategy", "bfd")
+        dataset = pack_dataset(
+            dataset.select_columns(used_column_names),
+            max_seq_length,
+            **_pack_kwargs,
+        )""",
+            )
             function = function.split("\n")
             function = "\n".join(" " * 4 + x for x in function)
             function = function.replace("def sft_prepare_dataset", "def _prepare_dataset")
@@ -2120,19 +2170,21 @@ def grpo_trainer_compute_loss(function_name, function):
             logits_to_keep,
             batch_size = None,
             compute_entropy = False,
-            compute_efficient = False: self._get_per_token_logps(
-                model, input_ids, attention_mask, logits_to_keep, compute_efficient
+            compute_efficient = False: (
+                self._get_per_token_logps(
+                    model, input_ids, attention_mask, logits_to_keep, compute_efficient
+                )
+                if hasattr(self, "_get_per_token_logps")
+                else self._get_per_token_logps_and_entropies(
+                    model,
+                    input_ids,
+                    attention_mask,
+                    logits_to_keep,
+                    batch_size,
+                    compute_entropy,
+                    compute_efficient,
+                )[0]
             )
-            if hasattr(self, "_get_per_token_logps")
-            else self._get_per_token_logps_and_entropies(
-                model,
-                input_ids,
-                attention_mask,
-                logits_to_keep,
-                batch_size,
-                compute_entropy,
-                compute_efficient,
-            )[0]
         )  # logps
 
         per_token_logps = get_logps_func(
diff --git a/unsloth/trainer.py b/unsloth/trainer.py
index 83cb1758f0..61d41aad21 100644
--- a/unsloth/trainer.py
+++ b/unsloth/trainer.py
@@ -100,6 +100,10 @@ PADDING_FREE_BLOCKLIST = {
     "gemma2",  # - gemma2:  Uses slow_attention_softcapping which has torch.compile issues
     "gpt_oss",  # - gpt_oss: Uses Flex Attention which doesn't handle padding_free correctly
 }
+# Hybrid linear-attention / state-space models (Qwen3.5, Qwen3-Next, ...) carry a
+# recurrent gated-delta state plus a causal conv1d. Sample packing / padding-free
+# flattens the batch, so those ops leak state across sequence boundaries. Detected
+# structurally by _is_hybrid_linear_attention_model rather than by model name.
 
 
 def _should_pack(config) -> bool:
@@ -137,6 +141,132 @@ def _should_skip_auto_packing_error(exc: Exception) -> bool:
     return any(msg in message for msg in _AUTO_PACK_SKIP_MESSAGES)
 
 
+_VISION_DATASET_KEYS = frozenset(
+    {
+        "image",
+        "images",
+        "image_grid_thw",
+        "image_position_ids",
+        "image_sizes",
+        "mm_token_type_ids",
+        "pixel_attention_mask",
+        "pixel_position_ids",
+        "pixel_values",
+        "pixel_values_videos",
+        "video",
+        "videos",
+        "video_grid_thw",
+    }
+)
+
+
+def _is_vlm_config(config, model_types = ()) -> bool:
+    if any(
+        hasattr(config, attr)
+        for attr in ("vision_config", "img_processor", "image_token_index", "projector_config")
+    ):
+        return True
+
+    architectures = getattr(config, "architectures", None) or ()
+    try:
+        from transformers.models.auto import modeling_auto
+
+        mappings = (
+            getattr(modeling_auto, "MODEL_FOR_IMAGE_TEXT_TO_TEXT_MAPPING_NAMES", {}) or {},
+            getattr(modeling_auto, "MODEL_FOR_VISION_2_SEQ_MAPPING_NAMES", {}) or {},
+        )
+        registry_types = set().union(*(mapping.keys() for mapping in mappings))
+        registry_classes = set().union(*(mapping.values() for mapping in mappings))
+        config_types = set(model_types or ())
+        model_type = getattr(config, "model_type", None)
+        if model_type is not None:
+            config_types.add(model_type)
+        if not config_types.isdisjoint(registry_types) or any(
+            architecture in registry_classes for architecture in architectures
+        ):
+            return True
+    except Exception:
+        pass
+    return any(
+        isinstance(architecture, str) and architecture.endswith("ForVisionText2Text")
+        for architecture in architectures
+    )
+
+
+def _is_vision_dataset(dataset, *, unknown_is_vision = False) -> bool:
+    if dataset is None:
+        return False
+    column_names = getattr(dataset, "column_names", None)
+    if column_names is not None:
+        return not _VISION_DATASET_KEYS.isdisjoint(column_names)
+    # Unknown-schema streams cannot be safely probed without potentially dropping a sample.
+    return unknown_is_vision
+
+
+def _is_vision_eval_dataset(dataset, *, unknown_is_vision = False) -> bool:
+    if isinstance(dataset, dict):
+        return any(
+            _is_vision_dataset(split, unknown_is_vision = unknown_is_vision)
+            for split in dataset.values()
+        )
+    return _is_vision_dataset(dataset, unknown_is_vision = unknown_is_vision)
+
+
+_HYBRID_CONFIG_MARKERS = (
+    "linear_conv_kernel_dim",
+    "linear_key_head_dim",
+    "linear_value_head_dim",
+    "full_attention_interval",
+)
+
+
+def _is_hybrid_linear_attention_model(model) -> bool:
+    """Detect models mixing linear-attention / state-space mixers (gated-delta,
+    Mamba-style) with a causal conv1d, e.g. Qwen3.5 / Qwen3-Next. Packing and
+    padding-free flatten the batch, and those recurrent + conv ops leak state
+    across sequence boundaries, so they must not be packed. Uses composite
+    structural evidence rather than a model-name match."""
+    if model is None:
+        return False
+
+    # Config-level: explicit hybrid layer schedule or linear-attn markers.
+    for config in (
+        getattr(model, "config", None),
+        getattr(getattr(model, "config", None), "text_config", None),
+    ):
+        if config is None:
+            continue
+        layer_types = getattr(config, "layer_types", None)
+        if isinstance(layer_types, (list, tuple)) and any(
+            isinstance(t, str) and "linear_attention" in t for t in layer_types
+        ):
+            return True
+        if any(hasattr(config, marker) for marker in _HYBRID_CONFIG_MARKERS):
+            return True
+
+    # Module-level: a mixer carrying a recurrent gated-delta op plus a conv1d.
+    named_modules = getattr(model, "named_modules", None)
+    if named_modules is None:
+        return False
+    seen = set()
+    for _, module in named_modules():
+        if id(module) in seen:
+            continue
+        seen.add(id(module))
+        cls = type(module).__name__
+        if not (
+            cls.endswith("GatedDeltaNet") or "LinearAttention" in cls or cls.endswith("Mamba2Mixer")
+        ):
+            continue
+        has_recurrent = any(
+            hasattr(module, attr)
+            for attr in ("chunk_gated_delta_rule", "recurrent_gated_delta_rule", "A_log")
+        )
+        if has_recurrent and hasattr(module, "conv1d"):
+            return True
+    return False
+
+
 # Unsloth gradient accumulation fix:
 from transformers import __version__ as transformers_version, ProcessorMixin
 
@@ -498,30 +628,43 @@ def _patch_sft_trainer_auto_packing(trl_module):
         else:
             config_arg = kwargs.get("args")
 
-        model = kwargs.get("model")
-        is_unsupported_model = False
+        model = args[0] if len(args) >= 1 else kwargs.get("model")
         is_vlm = False
+        is_unsupported_model = False
+        is_hybrid = False
         if model is not None:
             model_config = getattr(model, "config", None)
             if model_config is not None:
                 model_types = get_transformers_model_type(model_config)
                 is_unsupported_model = any(x in PADDING_FREE_BLOCKLIST for x in model_types)
+                is_vlm = _is_vlm_config(model_config, model_types)
+            is_hybrid = _is_hybrid_linear_attention_model(model)
 
-                architectures = getattr(model_config, "architectures", None)
-                if architectures is None:
-                    architectures = []
-                is_vlm = any(x.endswith("ForConditionalGeneration") for x in architectures)
-                is_vlm = is_vlm or hasattr(model_config, "vision_config")
-
-        processing_class = kwargs.get("processing_class") or kwargs.get("tokenizer")
-        data_collator = kwargs.get("data_collator")
+        processing_class = (
+            args[5] if len(args) >= 6 else kwargs.get("processing_class") or kwargs.get("tokenizer")
+        )
+        data_collator = args[2] if len(args) >= 3 else kwargs.get("data_collator")
+        train_dataset = args[3] if len(args) >= 4 else kwargs.get("train_dataset")
+        eval_dataset = args[4] if len(args) >= 5 else kwargs.get("eval_dataset")
+        is_processor = isinstance(processing_class, ProcessorMixin)
+        is_auto_processor_vlm = is_vlm and processing_class is None
+        is_vision_dataset = (
+            data_collator is None
+            and not is_processor
+            and (
+                _is_vision_dataset(train_dataset, unknown_is_vision = is_vlm)
+                or _is_vision_eval_dataset(eval_dataset, unknown_is_vision = is_vlm)
+            )
+        )
 
         # Disable padding-free for VLMs / custom collators / blocklisted models
         blocked = (
             (data_collator is not None)
-            or isinstance(processing_class, ProcessorMixin)
-            or is_vlm
+            or is_processor
+            or is_auto_processor_vlm
+            or is_vision_dataset
             or is_unsupported_model
+            or is_hybrid
             or (
                 os.environ.get("UNSLOTH_RETURN_LOGITS", "0") == "1"
             )  # Disable padding free on forced logits
@@ -535,10 +678,14 @@ def _patch_sft_trainer_auto_packing(trl_module):
 
         if blocked and requested_pack:
             reason = "custom data collator"
-            if data_collator is None and isinstance(processing_class, ProcessorMixin):
+            if data_collator is None and is_processor:
                 reason = "processor-based model"
-            elif is_vlm:
-                reason = "vision-language model"
+            elif is_auto_processor_vlm:
+                reason = "vision-language model with auto processor"
+            elif is_vision_dataset:
+                reason = "vision dataset"
+            elif is_hybrid:
+                reason = "hybrid linear-attention model"
             elif is_unsupported_model:
                 reason = f"unsupported model type(s): {', '.join(model_types)}"
             message = f"Unsloth: Sample packing skipped ({reason} detected)."