[BUG] Setting configured: Opus 4.6, Actual model being used: Sonnet 4.5

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?

Setting configured: Opus 4.6
Actual model being used: Sonnet 4.5 (claude-sonnet-4-5-20250929)
Persists across new conversations and application restarts
Platform: Windows 10 64-bit (platform identifier: win32)

What Should Happen?

Actual model being used must be Opus 4.6

Error Messages/Logs

Steps to Reproduce

run claude setting Opus 4.6 but the actual model being used is Sonnet 4.5

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.38

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

VS Code integrated terminal

Additional Information

_No response_