[BUG] Old plan getting presented like a new plan, even after discarding/starting a new one

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?

I thought this happened because we didn't start on a new plan, but even if we delete or start on a new one, the old plan still gets presented.

What Should Happen?

Every time we move into a new thing, a new plan gets created and the right one gets presented with an accepting prompt, not an old one.

Error Messages/Logs

Steps to Reproduce

Work enough with Claude Code.

Claude Model

Not sure / Multiple models

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.15

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Other

Additional Information

This happens to me on the VS Code extension; I do believe it happens in CLI too.