Claude in Chrome — "extension not connected" from cloud Cowork session despite full setup

Environment: macOS, Chrome; Cowork session running in the cloud; Claude Desktop app connected (remote-devices file tools work fine in the same session).

Problem: All mcp__claude-in-chrome__* calls return "Browser extension is not connected." tabs_context_mcp intermittently returns a tab, but the next navigate then fails with "extension not connected" or "tab no longer exists"; mostly every call fails.

Steps already tried (no effect): enabled all permissions in chrome://extensions (incl. debugger + site access), signed into the Claude side panel with the same account, restarted Chrome multiple times, and fully removed + reinstalled the extension from the Chrome Web Store. Same Claude account throughout.

Expected: cloud session should drive local Chrome per the "Get started with Claude in Chrome" docs (desktop app open + connected, which it is).

Actual: persistent "extension not connected"; device-bridge file tools in the same session work normally.