[BUG] Persistent "update available" notification despite being on latest version

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?

Running Claude Code version 2.1.152 (confirmed via claude --version).

Getting persistent "update available" notification on every launch, despite running winget upgrade before launching
and confirming no updates are available.

What Should Happen?

No update notification when already on the latest version, or at minimum, show which version the notification is
referring to.

Error Messages/Logs

Steps to Reproduce

1. Run winget upgrade Anthropic.Claude (shows no updates available)
2. Launch Claude Code
3. Receive "update available" notification (doesn't specify which version)

Claude Model

Sonnet (default)

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

2.1.152

Platform

AWS Bedrock

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

This is not a duplicate because previous reports have been closed and not addressed.

• winget show Anthropic.Claude --versions shows the latest version as 1.9255.2, but I'm running 2.1.152
• Appears to be a version numbering scheme change (1.x → 2.x) that may have broken the update checker
• Notification is not blocking but appears on most launches