[BUG] weird random characters

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?

After running the agent for a while in Google Antigravity on Mac OS (apple silicon), the characters get messed up and change color or get swapped out with characters from another alphabet:

<img width="697" height="1009" alt="Image" src="https://github.com/user-attachments/assets/5da292bb-55cd-4d2a-bbf9-3ac4aa29a8b8" />

What Should Happen?

Claude shouldn't randomly replace characters with characters from another font library.

Error Messages/Logs

None that I can find.

Steps to Reproduce

Run claude CLI in Google Antigravity for a couple of days. open multiple integrated terminals, each with a Claude Code CLI instance running.

You'll start to see the font change.

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.1.4.2

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

VS Code integrated terminal

Additional Information

This also happened in Google Antigravity a few months ago, but appeared to have been resolved. now it's back. Seems to be tied to the number of instances of claude that are running combined with the number of days the IDE has been open with multiple agents running.