Apple family sharing

Do you perhaps have an Apple Music subscription through a mobile provider, or with Apple directly?

Try this. Check if it is working after each step.

Restart your iOS device. 

Turn off iCloud Music Library and then turn it back on.

Sign out of the iTunes Store and then sign back in.

Please elaborate.

Family Sharing allows certain services to be shared in a small group. To add Apple Music to a Family Sharing plan, the Family group organizer should get the Apple Music Family subscription. The Apple Music Individual and Student subscriptions can’t be shared this way. If the family organizer already subscribes to Apple Music, he or she can change the subscription type. The other group members do not have to subscribe; they get access to the service by being part of the group.

Family Sharing - Apple Support

Set up Family Sharing - Apple Support

Get an Apple Music Family subscription - Apple Support

Manage your Apple Music subscription - Apple Support