Quick Flow Stalling Out in Front End

Q&A
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1

I’m running into what appears to be a UI synchronization issue in Amazon Quick Flows and wanted to see if anyone else has experienced this or found a workaround.

What I’m Seeing

The flow appears to stall indefinitely at a chunking step in my flow, but only in the UI. The progress indicator never advances, and the final output is not displayed to the user.

However, when reviewing the execution details through the chatbot and backend outputs, all processing appears to have completed successfully.

Backend Status

The flow successfully:

  • Processed 2 uploaded files
  • Completed carrier identification
  • Built context successfully
  • Generated page counts and ranges
  • Completed extraction across all page ranges
  • Consolidated extraction results
  • Calculated confidence scores
  • Generated the final output table
  • Produced the final sales summary

No backend errors, timeouts, or failed reasoning steps were identified.

Frontend Behavior

The UI:

  • Stops at Extraction Consolidator stage
  • Does not advance the progress indicator
  • Does not render the final output
  • Gives the appearance that processing is still running or stalled

The chatbot can still access the completed output, which suggests the processing itself finished successfully.

Suspected Cause

My current theory is that this may be a frontend/backend state synchronization issue where:

  1. Backend execution completes normally.
  2. Completion events or status updates are not reaching the frontend.
  3. The UI remains locked on the Extraction Consolidator state even though later steps have already executed.

Questions for the Community

Has anyone experienced:

  • Flows appearing stuck while processing actually completes?
  • Progress indicators failing to advance after a reasoning group or consolidator step?
  • Long-running flows losing synchronization with the UI?
  • Any known issues with polling, WebSocket connections, or frontend state updates?

Additional Context

This is not a true processing failure. The backend completes all work and generates valid outputs. The issue seems isolated to the frontend’s ability to recognize or display that completion. I have rebuilt the flow from scratch and it is still doing it. Additionally, it is doing the same thing on similar flows and for a colleague that is also using them.

Any troubleshooting suggestions, diagnostic locations, or known fixes would be greatly appreciated.

2

Hi @ajp829,

Welcome to the Quick Community! I would suggest checking your browser DevTools and look in the Network tab to see if there are any HTTP requests returning timeouts/errors. Although everything is working on the backend, it might prove helpful to check in case that could be affecting the stalling frontend behavior. Feel free to also try clearing your browser cache to ensure that is not affecting the result as well.

Hope this helps and please let me know if you’re still facing the same behavior!

3

Hi @ajp829,

Hope everything is well with you! Just checking back in since this thread hasn’t received a response in a while. Was Luis’s reply helpful to you or were you able to find a solution yourself in the meantime? Please help the community by marking this answer as “Solution” or following up in general within the next 3 business days!

4

Hi @ajp829,

Since I haven’t received any further updates from you, I’ll treat this inquiry as complete at this time. Please feel free to create a new post if you have more questions.

Thank you.