[BUG] changing to `/tui default` while a background process is running, kills that background process

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?

When I exit to the default mode using /tui default while a background process is running, it gets killed, likely because claude kills itself and resumes again.

My reason for exitting is that while in /tui fullscreen mode, the log for the background shell is not visible properly. It clips to 3 lines and I want to see more, hence I wanted to exit.

My terminal is kitty

kitty 0.44.0 created by Kovid Goyal

What Should Happen?

It should retain any and all background processes and change to the /tui default rendering mode

Error Messages/Logs

Steps to Reproduce

Change to /tui fullscreen
Ask claude to run a background agent/shell
Change to /tui default

Poof, the background shell is now gone

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

2.1.114

Claude Code Version

2.1.133 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Other

Additional Information

_No response_