diff --git a/studio/frontend/src/features/chat/api/chat-adapter.ts b/studio/frontend/src/features/chat/api/chat-adapter.ts
index 6dc143662b..73411450d8 100644
--- a/studio/frontend/src/features/chat/api/chat-adapter.ts
+++ b/studio/frontend/src/features/chat/api/chat-adapter.ts
@@ -933,7 +933,29 @@ export function createOpenAIStreamAdapter(): ChatModelAdapter {
           ),
       );
 
-      const outboundMessages = messages
+      // Two-pass build so a refused assistant turn drops the user
+      // message that triggered it as well. Anthropic's refusal-handling
+      // guidance is explicit that leaving the offending user prompt in
+      // context causes the next request to re-trigger the classifier;
+      // returning null on just the assistant side was not enough.
+      const survivingMessages: RunMessage[] = [];
+      for (const message of messages) {
+        if (
+          message.role === "assistant" &&
+          collectTextParts(message)
+            .join("\n")
+            .includes(ANTHROPIC_REFUSAL_SENTINEL)
+        ) {
+          const last = survivingMessages.at(-1);
+          if (last && last.role === "user") {
+            survivingMessages.pop();
+          }
+          continue;
+        }
+        survivingMessages.push(message);
+      }
+
+      const outboundMessages = survivingMessages
         .map(toOpenAIMessage)
         .filter((message): message is NonNullable<typeof message> =>
           Boolean(message),
diff --git a/studio/frontend/src/features/chat/utils/chat-settings-storage.ts b/studio/frontend/src/features/chat/utils/chat-settings-storage.ts
index e07e1ddb1d..eea3e49d5e 100644
--- a/studio/frontend/src/features/chat/utils/chat-settings-storage.ts
+++ b/studio/frontend/src/features/chat/utils/chat-settings-storage.ts
@@ -140,6 +140,14 @@ function sanitizeInferenceParams(
   if (typeof value.trustRemoteCode === "boolean") {
     params.trustRemoteCode = value.trustRemoteCode;
   }
+  // fastMode is in PERSISTED_INFERENCE_PARAM_KEYS but used to be
+  // stripped here because the sanitizer only kept numeric fields plus
+  // the two explicit string/bool fields above. Save the toggle the
+  // same way trustRemoteCode is saved so the value survives reload
+  // and the /api/chat/settings round-trip.
+  if (typeof value.fastMode === "boolean") {
+    params.fastMode = value.fastMode;
+  }
   return hasKeys(params) ? params : undefined;
 }