diff --git a/web/src/pages/next-chats/chat/chat-box/next-multiple-chat-box.tsx b/web/src/pages/next-chats/chat/chat-box/next-multiple-chat-box.tsx
index 22cf808fd4..634404f5ff 100644
--- a/web/src/pages/next-chats/chat/chat-box/next-multiple-chat-box.tsx
+++ b/web/src/pages/next-chats/chat/chat-box/next-multiple-chat-box.tsx
@@ -158,9 +158,22 @@ const ChatCard = forwardRef(function ChatCard(
   const { data: currentDialog } = useFetchChat();
   const findLlmByUuid = useFindLlmByUuid();
 
+  // Each card must keep its own independently selected model after the initial
+  // sync. Without this guard, clicking "Apply" in one card patches the dialog
+  // (which invalidates [FetchChat] and refetches currentDialog), and the
+  // changed currentDialog.llm_id would then overwrite every other card's
+  // llm_id via this effect. Sync only when dialogId changes (initial load or
+  // conversation switch), not when currentDialog.llm_id changes due to Apply.
+  const syncedDialogIdRef = useRef<string | undefined>(undefined);
   useLayoutEffect(() => {
-    form.setValue('llm_id', currentDialog?.llm_id || '');
-  }, [currentDialog?.llm_id, form]);
+    if (
+      syncedDialogIdRef.current !== dialogId &&
+      currentDialog?.llm_id
+    ) {
+      form.setValue('llm_id', currentDialog.llm_id);
+      syncedDialogIdRef.current = dialogId;
+    }
+  }, [currentDialog?.llm_id, dialogId, form]);
 
   const isLatestChat = idx === chatBoxIds.length - 1;
 
@@ -176,6 +189,7 @@ const ChatCard = forwardRef(function ChatCard(
       params: {
         ...currentDialog,
         llm_id: llmId,
+        tenant_llm_id: llmId,
         llm_setting: {
           ...omit(values, 'llm_id'),
           model_type: findLlmByUuid(llmId)?.model_type || 'chat',