diff --git a/studio/frontend/src/components/assistant-ui/thread.tsx b/studio/frontend/src/components/assistant-ui/thread.tsx
index c33ec403f4..85989b1a41 100644
--- a/studio/frontend/src/components/assistant-ui/thread.tsx
+++ b/studio/frontend/src/components/assistant-ui/thread.tsx
@@ -1315,7 +1315,12 @@ const ComposerToolsMenu: FC<{ side?: "top" | "bottom" }> = ({
     const store = useChatRuntimeStore.getState();
     store.setActiveThreadId(null);
     store.setContextUsage(null);
-    navigate({ to: "/chat", search: { compare: crypto.randomUUID() } });
+    // crypto.randomUUID is undefined in non-secure contexts (HTTP over a LAN IP).
+    const compareId =
+      typeof globalThis.crypto?.randomUUID === "function"
+        ? globalThis.crypto.randomUUID()
+        : `${Date.now()}-${Math.random().toString(36).slice(2, 10)}`;
+    navigate({ to: "/chat", search: { compare: compareId } });
   }, [navigate]);
 
   return (
diff --git a/studio/frontend/src/features/chat/shared-composer.tsx b/studio/frontend/src/features/chat/shared-composer.tsx
index e7dbe94d95..01a6a27b2d 100644
--- a/studio/frontend/src/features/chat/shared-composer.tsx
+++ b/studio/frontend/src/features/chat/shared-composer.tsx
@@ -1038,6 +1038,8 @@ export function SharedComposer({
                           onSelect={() => {
                             setReasoningEnabled(false);
                             applyQwenThinkingParams(false);
+                            // Preserve thinking needs thinking on, so turn it off too.
+                            setPreserveThinking(false);
                           }}
                         >
                           <CheckIcon
@@ -1093,6 +1095,8 @@ export function SharedComposer({
                           const next = !reasoningEnabled;
                           setReasoningEnabled(next);
                           applyQwenThinkingParams(next);
+                          // Preserve thinking cannot run without thinking.
+                          if (!next) setPreserveThinking(false);
                           if (isKimiExternal && next && toolsEnabled) {
                             setToolsEnabled(false, { persist: false });
                           }
@@ -1113,7 +1117,13 @@ export function SharedComposer({
                       disabled={!modelLoaded}
                       onSelect={(e) => {
                         e.preventDefault();
-                        setPreserveThinking(!preserveThinking);
+                        const next = !preserveThinking;
+                        setPreserveThinking(next);
+                        // Preserve thinking requires thinking on.
+                        if (next) {
+                          setReasoningEnabled(true);
+                          applyQwenThinkingParams(true);
+                        }
                       }}
                     >
                       <CheckIcon