[BUG] VSCode Extension stops updating "Claude's Plan" block after several tasks in the same session

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 using plan mode in the VSCode extension, the "Claude's Plan" UI block initially works correctly, but after completing several planning tasks (3-5) within the same session, it stops showing the current plan and reverts to displaying an older plan.

After ~3-5 planning tasks in the same session, the block stops syncing with the current plan
It displays an older plan from earlier in the session (or a previous session)
This happens within the same tab/session, not across different sessions

What Should Happen?

"Claude's Plan" block should always display the current session's plan, regardless of how many tasks have been completed

Error Messages/Logs

Steps to Reproduce

Start a new session in VSCode extension
Enter plan mode and complete a planning task — works correctly
Complete another planning task — still works
Repeat for 3-5 tasks
At some point, the "Claude's Plan" block stops updating and shows an old plan instead of the current one

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.2 (Claude Code)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

VS Code integrated terminal

Additional Information

_No response_