Uninstalled apps appear in Focus Allow Notifications list

When I go to the Apps list, under Allow Notifications, while setting up a Focus, I can see 5 apps in the list that I don't even have installed. Some have never been installed on this device. Some have been completely withdrawn. These include the old "Game Center" app and Barclay's PingIt, which was withdrawn about 5 years ago.

Where are those "footpints" lurking?