Hello locksasa,
Thank you for reaching out to Apple Support Communities, and we'll be happy to help in any way we can. We understand you're having issues with sharing an Apple Music subscription with Family Sharing. Try the steps here to see if they resolve the issue: Add a family member to your shared subscriptions - Apple Support
"If you already set up Family Sharing
After you set up Family Sharing, eligible subscriptions are automatically shared with your family members. If your family members can't access a subscription, here's what to do:
- On your iPhone or iPad, go to Settings, then tap your name.
- Tap Subscriptions.
- Scroll down and make sure that Share with Family is turned on.
- Tap the subscription that you want to share.
- If the subscription is individual or student, upgrade your subscription to a family plan.
- If the subscription isn't made by Apple, it might not be eligible to share. To share a subscription, turn on Share with Family under Family Access. "
"Who is charged for the subscription?
If Purchase Sharing is turned on, the family organizer pays for everyone's subscriptions.*
If you're the family organizer and you don't want to pay for family members' purchases and subscriptions, you can turn off Purchase Sharing. When Purchase Sharing is turned off, everyone must use their own payment method. When Purchase Sharing is turned off, family members can share subscriptions, but they can't share individual purchases like apps or books."
We hope this helps.
Cheers!