[BUG] Plan mode unreliable

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?

The plan mode feature is getting worse week by week:

• claude doesn't enter plan mode when asked: "make a plan".
• switching to plan mode using shift+tab while claude is working should prevent claude from editing files but it doesn't
• claude edits files while in plan mode
• sometimes plans show outdated contents

What Should Happen?

Should work more reliably

Error Messages/Logs

Steps to Reproduce

• ask claude to "make a plan" after a convo
• while claude is working switch to plan mode, sometimes it keeps editing files

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.72

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

VS Code integrated terminal

Additional Information

_No response_