FaceTime notifications not displayed on Mac

Incoming FaceTime calls ring on iOS devices connected to the network(s), but not on the MacOS device, a Mac Studio. All devices are connected to the same networks. The "missed call" notification is displayed on the FT icon in the dock on the Mac. That is the only indication that a call has been made to the Apple ID signed in on the Mac. What we have checked:

1. That FT is turned on.
2. That notifications for FT are turned on in System Settings. All of them.
3. That no Focus is turned on.
4. That the Mac OS is up to date.
5. Completed a system restart (not a shut-down, but we're trying that next).

Any help is appreciated. Thanks.