[BUG] Cursor appears on a wrong line than intended

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?

Randomly the cursor shifts to a wrong line, clearly unintended behavior

What Should Happen?

The cursor should stay on the intended line

Error Messages/Logs

Steps to Reproduce

Happens randomly mid session, example:

<img width="665" height="283" alt="Image" src="https://github.com/user-attachments/assets/4cf63809-7957-43e3-8d29-28190f6280cf" />

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.20

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_