After purchasing Apple Music Family Plan it says that I've shared it with the family in the family sharing settings however won't work on other devices with a different Apple ID (the other apple ID is in the family sharing)
iPhone 12, iOS 14
Did you invite the other members to join? If so, did they accept that invitation? See the "Invite people to join your family" and "Join a family group" sections in:
Set up Family Sharing - Apple Support
Also, did they turn on "Sync Library" on their devices?
Turn on Sync Library with Apple Music - Apple Support
Did you invite the other members to join? If so, did they accept that invitation? See the "Invite people to join your family" and "Join a family group" sections in:
Set up Family Sharing - Apple Support
Also, did they turn on "Sync Library" on their devices?
Turn on Sync Library with Apple Music - Apple Support
All family members are in the family sharing and have accepted.
Apple Music won't sync to other devices
