Escape sequences ([110;1:3u) randomly inserted during prompt input

What version of Codex CLI is running?

codex-cli 0.115.0

What subscription do you have?

Pro

Which model were you using?

5.4 high fast

What platform is your computer?

macOS Darwin 25.3.0 arm64 arm

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

Ghostty + ZSH

What issue are you seeing?

When prompting the agent, escape sequences matching those described in this closed issue are randomly inserted at the cursor, e.g. [110;1:3u

What steps can reproduce the bug?

I believe the bug may be related to two codex agents in different split panes of the same window.

1. Split Ghostty window into four full-width panes, one on top of the other.
2. Panes 1 and 3 are codex agents working on separate projects/repositories
3. Pane 2 and 4 are surfaces for user commands relating to the repos being worked on in 1 and 3 respectively.
4. Prompt the agent in Pane 1
5. Begin prompting the agent in Pane 3 – it appears that the reasoning in Pane 1 (possibly the conclusion of this, specifically) causes escape sequences to be inserted at the cursor.

What is the expected behavior?

For this to not happen.

Additional information

_No response_