MCP re-auth occasionally does not allow new account selection when authenticating

[muchani11]

Describe the bug

I tried authenticating to an MCP server via re-auth (/mcp show -> Selecting the server -> r for re-auth), and after following the browser-based auth flow (which should have worked) I got this error message in the CLI - Streamable HTTP error: Error POSTing to endpoint:

This is the first issue - would like to get some insight into why this is happening (happened at roughly 10:40 AM PST on 5/13/26). Secondly, now, even when I use "r", it's no longer letting me reauth to the triage MCP server. No browser pop up appears so the auth is stuck in a failed loop.

Affected version

GitHub Copilot CLI 1.0.47

Steps to reproduce the behavior

1. /mcp show -> Select a server -> r for re-auth
2. During the account selection flow, this error must be reproduced - "Streamable HTTP error: Error POSTing to endpoint:"
3. Try pressing r again for reauthenticating and observe that the browser no longer pops up

Expected behavior

I would expect the browser to pop up every time a re-authentication is attempted

Additional context

• Shell (Windows PowerShell)
• OS (Windows 11 Enterprise)