Hey, this is a known issue and it’s been around for a while. Full thread here: MCP Allowlist doesn’t work, also can’t be edited MCP Allowlist doesn't work, also can't be edited
Root cause is that some internal flags get stuck in state.vscdb and override whatever you set in the UI.
On Windows there’s a community workaround, a PowerShell script from this post in the same thread: MCP Allowlist doesn't work, also can't be edited - #19 by helloworld2. Before running it, make sure Cursor is fully closed. The script creates a backup automatically. You’ll need sqlite3.exe, the download link is in that post too.
The team is aware of the issue. Let me know if the workaround helps.