Instructor with too much privilege

I have an instructor who for some reason can see and edit other instructors classes on Studio. I confirmed they don’t have Staff or Admin privileges in any of the classes. Any idea why this might be or how to debug it?

can you go to {LMS_HOST}/admin/auth/user/
find that user, and check if Staff status or Superuser status is ticked ?

Yes, that was it! Apparently I had set that a year ago and forgot about it!