“Instant Run” stops immediately with “get prompts → finished” (no actual execution)

### Custom Node Testing

- [x] I have tried disabling custom nodes and the issue persists (see [how to disable custom nodes](https://docs.comfy.org/troubleshooting/custom-node-issues#step-1%3A-test-with-all-custom-nodes-disabled) if you need help)

### Expected Behavior

“Instant Run” stops immediately with “get prompts → finished” (no actual execution)

This problem didn’t exist a few days ago with the same workflow.

other workflow like SDXL just work fine,can instant run.

The issue only appears when using instant/looping runs relate to video workflow.

Manual “Run” works fine every time.

Possibly related to websocket or preview callback timing in the new ComfyUI build?

This seems to be a recent regression, possibly tied to either:

The Video Combine node’s preview update timing, or

A new websocket handling change in ComfyUI’s recent commits.

Would appreciate if the devs could confirm if this is reproducible on their side.

### Actual Behavior

I’ve been debugging this for some days, and it seems not to be a local environment issue but a possible version-related bug.

When using Instant Run or any auto-looping execution mode, ComfyUI instantly logs:

get prompts
finish

but in less than one second, without actually executing the workflow.
However, if I run the same workflow manually (by pressing “Run”), everything works perfectly.

### Steps to Reproduce

Browsers tested：

❌ Edge (latest) → “get prompts / finish” loop

❌ Chrome (latest) → same behavior

❌ Firefox (latest) → same behavior

✅ Midori → works normally (but has its own UI bugs, see below)

Interestingly, only Midori allows continuous runs, but it fails to preview videos in the Video Combine node.
This makes me suspect the issue may be connected to the Video Combine node’s preview or websocket handling.
It feels like the preview process doesn’t finish properly before the next prompt is requested, causing the system to immediately report “finished” without real execution.

### Debug Logs

```powershell
What I’ve already tried：

-Created a fresh conda environment

-Reinstalled all required pip packages

-Tested with and without custom nodes

-Cloned a clean ComfyUI repo (no modifications)

-Fully updated to the latest ComfyUI version

Same issue persists across all clean installations.
```

### Other

Environment:

-Laptop Lenovo LOQ

-OS Windows 11 Home

-GPU RTX 4060 (8GB)

-Python: 3.12(Conda)

-ComfyUI: latest build (updated manually)

-Browser: Edge, Chrome, Firefox, Midori (tested)