FCP 12.0 takes a long time to close

I updated to FCP 12.0 yesterday. It works fine on my Mac Studio M4, but when I close the app, it takes a long time before it finally quits (about a minute), even when no library is open. Previous versions closed instantly. Tried to “delete preferences” and installing the app again, but no change.

Does anyone recognize this, or - better! - know how to solve this?