Thank you for your reply. Today the songs are playing as expected. If this begins to happen again we will create a bug report with the sysdiagnose, date and time.

Having a way to reset this Safari preference would be very helpful if someone wishes to be presented App Clip cards once more. Would love to hear if there is a way to do this! Thanks for any help!

This does work on an M1 Mac - confirmed with a few scaled down test projects.

The universalLinkURL - https://developer.apple.com/documentation/classkit/clscontext/linking_directly_to_assignments?language=occ with onOpenURL was the answer for me here