Multiple sub-agents + typing randomly breaks TUI

What version of Codex CLI is running?

v0.128.0

What subscription do you have?

Pro

Which model were you using?

irrelevant

What platform is your computer?

Windows

What terminal emulator and version are you using (if applicable)?

Windows Terminal

What issue are you seeing?

Codex stopped reacting to any input and updating output in the middle of long multi-agents flow. The cursor is blinking but nothing else works. I can see the progress by resuming the same session in another instance but I it doesn't show sub-agents.
Similar issue happened to me several times previously when I switch to sub-agent, then tried to switch back, started typing "/ag" and tui was blocked the same way.

It doesn't matter how long I wait, it just stays this way forever.

What steps can reproduce the bug?

It just happens randomly. I'm certain that it's threading synchronization issue. It only happens when I run 4+ sub-agents in parallel. Probably it's easier to reproduce if you run 10+ and keep actively switching between them and typing in the main context.

Uploaded thread: 019df509-ba14-7320-97b7-a5e14eb4f5a2

What is the expected behavior?

TUI keeps working without hanging

Additional information

_No response_