[Windows desktop] Chat view stops rendering replies ("stream refused ... parked until focus"); persists after update to 2.9939.4

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

The chat window in the desktop app stops showing new replies, and sometimes shows "Failed to send". The same conversation shows every message correctly on web and mobile. Linked-device tools keep working during the freeze, so the network and the app backend are alive; only the chat view is stuck.

Because it now occurs with no network errors at all, it looks like the parked stream is not resumed when the window is not focused, rather than a connectivity problem.

Environment: Windows 11, locale he-IL, MSIX (Windows Store) package. Was 2.9939.2 (installed 25/09/2026), auto-updated to 2.9939.4 on 29/09/2026 06:32. Wi-Fi Realtek 8821CE.

What Should Happen?

The chat view should keep rendering new replies (as web and mobile do for the same conversation), and a parked stream should resume on its own without needing Ctrl+R or a relaunch.

Error Messages/Logs

Evidence from main.log / claude.ai-web.log:
- 29/09 (on 2.9939.4): zero network errors, yet 5 occurrences of
  "[COMPLETION] [bardhub] stream refused: creation wait exhausted — parked until retry, send, focus, or adoption"
  at 06:59:29, 07:11:48, 07:12:00, 07:17:16, 08:25:35. User reported the freeze at ~07:50.
- Same message on earlier days: 22/09: 3, 23/09: 7, 27/09: 2, 28/09: 2.
- 28/09 (on 2.9939.2): 27 x "stream silent past heartbeat window", clustered 10:06–10:18 and 16:35–16:44. Windows event log shows Wi-Fi connected throughout.
- 29/09 06:32: "[event-loop-stall] main process blocked for 1436ms" and "claudeURLHandler: initial mainView load loadURL rejected { code: 'ERR_FAILED' }" right after the update.

Steps to Reproduce

1. Use the Claude desktop app on Windows 11 (MSIX package, 2.9939.4) in a normal chat/Cowork conversation.
2. Keep working; the issue appears intermittently, apparently while the window is not focused.
3. The chat view stops showing new replies (sometimes "Failed to send"), while the same conversation on web/mobile shows all messages.
4. Ctrl+R, or a full Quit from the tray and relaunch, restores all messages.

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

Claude Desktop 2.9939.4 (Windows MSIX); also seen on 2.9939.2

Platform

Other

Operating System

Windows

Terminal/Shell

Other

Additional Information

Workaround: Ctrl+R, or a full Quit from the tray and relaunch, restores all messages.

Related: #91988 (separate startup issue, same machine).
Logs available on request.