Claude in Chrome extension shows "Browser extension is not connected" — persists after restart, extension update, and connector retoggle

Environment:

OS: Windows
Browser: Google Chrome (please fill in version — chrome://settings/help)
Claude Desktop app version: (please fill in — check in Settings)
Extension version: (please fill in — check in chrome://extensions)

Description:
The Claude in Chrome extension was working earlier in this session (successfully used for browser automation tasks) and then disconnected mid-session. All subsequent connection attempts return:

Browser extension is not connected. Please ensure the Claude browser extension is installed and running (https://claude.ai/chrome), and that you are logged into claude.ai with the same account as Claude Code.

Steps already tried (none resolved the issue):

Fully quit and restarted Chrome
Updated the extension via chrome://extensions (Developer mode → Update)
Restarted Chrome again after the update
Toggled the "Claude in Chrome" connector off and on in Claude Desktop → Settings → Connectors (with Chrome open at the time)

Expected behavior: Extension reconnects and browser automation tools work again.

Actual behavior: Connection attempts consistently fail with the same "not connected" error, with no change across any of the troubleshooting steps above.

Additional context: This started mid-session without any obvious trigger (no Chrome crash, no manual disconnect) — the extension simply stopped responding between one tool call and the next.