Getting 400 when trying to use the dev mode mcp

I’m trying a simple prompt:
use my selection on figma to design the current unfollow button.

But I’m getting this issue:

[2025-07-03T12:18:55.414Z] [info] [GitHubCopilot] [27618] window/logMessage: {
  "message" : "[fetchChat] Unhandled status from server: 400 Bad Request\n",
  "type" : 1
}

I’m using GitHub Copilot for Xcode and Claude Sonnet 4, and all I get is:

the mcp seems to be defined correct.