Why is my Family Sharing for Apple Music not working in other devices?

Have you shared it? You can choose which eligible App Store subscriptions you share with family members. From: Share Apple and App Store subscriptions with family members on iPod touch - Apple Support and Share Apple and App Store subscriptions with family members on iPhone - Apple Support

Here's a list of standard things to try when a feature is not working:

Make sure the software is up to date on all devices involved.

Update macOS on Mac - Apple Support

Update your iPhone or iPad - Apple Support

Sometimes it helps to have the devices involved take a fresh look at settings:

● If this is a service, try disabling it and turning it back on.

● Try signing out of accounts and back in again.

Sign out of iCloud on your iPhone, iPad, iPod touch, Apple TV, or Mac - Apple Support

Sign in with your Apple ID - Apple Support

If you have more than one Apple ID, don't forget you may be signed into other accounts too for special services such as iMessage and Media & Purchases.

● Restarting is a simple step that can resolve many unexpected behaviors.

iPhone: Restart your iPhone - Apple Support then choose your model.

iPad: Restart your iPad - Apple Support

Mac: Ways to start up your Mac - Apple Support

Try using other equipment if possible. I have seen several cases where somebody tried to do something on one item of equipment and failed, but then tried on a different item of equipment and succeeded.

Sometimes it can take some time for changes to propagate through the system and waiting may help ( e.g., Family Sharing of Apple News+ - Apple Community ). If a problem persists, particularly over several days, try contacting Apple for assistance:

Click here --> Choose your country or region - Official Apple Support Select your country, then a product. If you don't see one that handles your issue then keep experimenting with selections until you reach one that gets you a chat session or a telephone call and get the representative to redirect you.

or:

"See a list of Apple phone numbers around the world."

Click here --> Contact Apple for support and service - Apple Support