[BUG] Claude in Chrome: tools report "Browser extension is not connected" although extension, native host and socket are running (Linux)

What's wrong?

In a Claude Code session, every Claude in Chrome tool call fails with:

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.

list_connected_browsers returns []. This persisted across 8 attempts over about 10 minutes, including after running /chrome in the session (which printed no output).

What should happen?

The session should attach to the running Chrome extension so the browser tools work.

What I verified

• Chrome is running and the Claude extension (fcoeoabgfenejglbffodgkkbkcdhcgfn) is installed in both Chrome profiles (Default and Profile 1).
• The native host process is running: claude --chrome-native-host.
• The bridge socket exists: /tmp/claude-mcp-browser-bridge-<user>/<pid>.sock.
• The native messaging manifest com.anthropic.claude_code_browser_extension.json is present under ~/.config/google-chrome/NativeMessagingHosts/ and points to ~/.claude/chrome/chrome-native-host.
• claude.ai in the same Chrome is signed in with the same account as Claude Code (Pro plan).

Steps to reproduce

1. Start Chrome with the Claude extension installed and signed in.
2. Start a Claude Code session and ask for a browser task.
3. Claude calls tabs_context_mcp with createIfEmpty: true.
4. The call returns "Browser extension is not connected"; list_connected_browsers returns [].
5. Run /chrome, retry: same result.

Environment

• Claude Code: 2.1.289
• OS: Ubuntu 24.04.4 LTS, kernel 7.0.0-31-generic
• Chrome: 152.0.7977.64 (/opt/google/chrome/chrome)
• Two Chrome profiles in use

Not yet tried

Fully restarting Chrome and relaunching with claude --continue --chrome.