Response with strange em dash

What version of Codex is running?

0.58.0

What subscription do you have?

plus

Which model were you using?

gpt-5.1-codex

What platform is your computer?

Darwin 25.1.0 arm64 arm

What issue are you seeing?

Sometimes codex response with em dash(—) oddly.

<img width="443" height="62" alt="Image" src="https://github.com/user-attachments/assets/013990e1-61fd-46d9-9c40-dc0664a90275" />

What steps can reproduce the bug?

I don't know how to reproduce but it happens very often.

What is the expected behavior?

_No response_

Additional information

_No response_