Self-managed GitLab instance: plugin MCP defaults to gitlab.com and blocks normal local setup

I installed the GitLab plugin in Cursor to work with my self-managed GitLab instance, not gitlab.com.

When I tried to authenticate MCP, the browser opened gitlab.com instead of my instance. I also ended up with two GitLab MCP entries in settings: one I had configured myself (which worked), and one from the plugin pointing at gitlab.com (which didn't want to authenticate with). The plugin one only had a "Connect" button — no way to turn it off. So even though my local setup was authenticated, Cursor kept nudging me to auth against gitlab.com when using the agent.

The README mentions self-managed setup — copy .mcp.json.self-managed.example, change the URL, etc. — but there's no obvious way to do that from Cursor. The file isn't in my project; it's buried somewhere under ~/.cursor/plugins/cache/.... I only figured that out after a lot of digging.

What eventually worked: edit that cached .mcp.json to point at my instance (https://<self-managed-instance>/api/v4/mcp), remove the duplicate from my own ~/.cursor/mcp.json, restart Cursor, and auth again. After that, MCP worked fine against self-managed GitLab.

One catch: that fix doesn't feel permanent. The file lives in Cursor's plugin cache, not somewhere I manage myself, so I'd expect a plugin update to overwrite it and put gitlab.com back. I haven't hit that yet, but it's another reason the self-managed path feels fragile — you can get it working and then lose it on the next update without any warning.

It feels like the plugin assumes gitlab.com by default, and the self-managed path is documented but not really supported in practice unless you know where to look. Easy to misconfigure, easy to auth the wrong instance.

I checked the issue tracker before filing — only #1 exists and it's unrelated (MCP search docs).

If it helps, some ideas on how to solve it: expose the MCP URL in settings, or let people disable the bundled gitlab.com server when they're on self-managed.