[Bug] VS Code extension automatically locks editor group, causing unwanted splits

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report
• [x] I am using the latest version of Claude Code

What's Wrong?

When using the Claude Code VS Code extension with claudeCode.preferredLocation: "panel", the extension automatically locks the editor group. This causes all subsequently opened files to create a new split instead of opening as a new tab in the same group.

The lock icon appears on the editor group, and VS Code's "Open to the Side" behavior is triggered for every new file.

What Should Happen?

Opening files should add them as new tabs in the existing editor group, without creating splits. The editor group should not be locked automatically.

Steps to Reproduce

1. Install Claude Code extension
2. Set "claudeCode.preferredLocation": "panel" in settings.json (or leave default)
3. Open VS Code with any project
4. Open a file from the explorer (single click or double click)
5. Open a second file from the explorer

Result: The second file opens in a new split. A lock icon is visible on the editor group.

Workaround

Manually unlock the editor group via Cmd+Shift+P → "View: Unlock Editor Group". However, this needs to be done every time VS Code is restarted or a new window is opened.

Claude Model

Sonnet (default)

Is this a regression?

Unknown

Claude Code Version

Latest

Platform

Anthropic API

Operating System

macOS 15 (Darwin 25.2.0)

Terminal/Shell

zsh

Additional Information

Disabling the Claude Code extension resolves the issue - editor groups are no longer locked automatically.