[Windows regression] Selected task with multiple active subagents freezes the app

What version of the Codex App are you using?

Affected version: 26.730.61309. The issue appeared after today's update from 26.727.51351.

What subscription do you have?

Pro

What platform is your computer?

Windows 11 x64 (10.0.26200). The affected task uses a WSL2 workspace.

What issue are you seeing?

After today's update, selecting a Codex task with multiple active subagents makes the app severely sluggish. With 12 active subagents, hover states stopped responding reliably and typing into text boxes became heavily delayed.

On one attempt to check back in on the affected task, the app froze completely for approximately 60–90 seconds before recovering.

The rest of Windows remained responsive. Switching to another chat in the same app restored normal hover and typing performance while the subagents continued running. The slowdown therefore appears tied to displaying the affected task, rather than to the overall system workload.

This is different from the system-wide input lag in #28855.

Steps to reproduce

1. Run several subagents concurrently in a Codex task (12 in this case).
2. Keep that task selected.
3. Hover over controls or type into a text box.
4. Observe severe UI lag; checking back in on the task may freeze the app completely for 60–90 seconds.
5. Switch to another chat without stopping the subagents.
6. Observe normal UI responsiveness.

Expected behaviour

The selected task should remain responsive while subagents run.