I subscribe to Apple One and am the Organizer of the Family Plan. Apple Music works fine on my phone but suddenly stopped working on my 2019 Mac Pro running Tahoe 26.7.1. I've applied all relevant updates, rebooted, etc.
I click on sign-in and enter my AppleID and password but nothing happens. It doesn't say the info is wrong or anything. I'm just in an endless loop where it keeps forcing me to try to sign-in to play anything but it never actually signs in.