I've had this issue off and on since 2022 and Apple Support can not help, the only way I have found to resolve this, is:
- Make sure you are signed out and the Apple Music player is closed.
- Go into the Apple Music Web Player on a browser and sign in on there.
- On the bottom left hand corner click the thing that says "Open in Music"
- Once the app opens, sign into your account on the app.
I've tried talking to apple support on the phone and the only thing they know to tell you is to log in and out or turn your device off and make sure your stuff is up to date which does nothing for this issue. This is the only resolution that I have figured out on my own. That being said, I've only tried it on the MacBook and iMac. I am not sure if it works for the iPhone/iPad as I have not had this issue on my phone or tablet, but it is worth a try considering Apple Support can only suggest what Bruno75 has outlined.