Chat not responding on os.envsn.com (infinite loading, no answer)

[dtomic15]

Summary

Chat UI is loading indefinitely and not answering prompts on os.envsn.com.

Impact

Users can type and submit prompts, but get no response in chat, which blocks core product usage.

Environment

• URL: https://os.envsn.com
• Browser: Chrome
• Observed date: 2026-02-18

Repro Steps

1. Open https://os.envsn.com.
2. Start a new chat.
3. Ask any question.
4. Observe spinner/loading state with no answer returned.

Actual

• Chat stays loading and no response is shown.

Expected

• Prompt should produce a model response in normal time.

Diagnostic Notes

• https://os.envsn.com/api/version returns 0.8.1.
• The previously-debugged Cloud Run endpoint returns a different version (0.7.2), indicating environment/version mismatch.
• During failure windows, UI keepalive/socket traffic may still be healthy while chat generation requests are missing or not completing.
• This suggests a frontend send-flow issue, host/routing mismatch, or backend mapping mismatch for os.envsn.com.

Suggested Investigation

1. Verify os.envsn.com points to the intended production backend (LB -> backend service -> app version parity).
2. In browser devtools on failure, confirm POST /api/chat/completions is emitted and inspect status/response.
3. Check backend logs for matching timestamp/request id for that POST path.
4. Confirm no stale frontend host-redirect/canonical-host logic is interfering with request submission.
5. Validate model/provider routing for this environment (provider available + credentials + timeout behavior).

Acceptance Criteria

• Prompt submission from os.envsn.com consistently triggers backend chat POST.
• Chat responses render successfully for basic prompts in Chrome.
• No infinite loading for normal requests.