I had a Family Sharing with a UK Apple ID as Organizer ("UK ID"), one adult member ("Adult"), and one child member ("Child"). The problem was that the payment was linked to a fourth, US-based Apple ID ("US ID"), not allowing any of us to do anything.
These are the steps I took:
- In the UK ID iCloud account, I removed the Adult from Family Sharing
- The Adult then set up a new Family Sharing in her iCloud account
- Adult invited the Child to join the new Family Sharing under her iCloud account
- UK ID accepted, so that the Child moved to the new Family Sharing under the Adult's iCloud (the UK ID Family Sharing now had zero members)
- UK ID Stopped Family Sharing in UK ID's iCloud (UK ID now does not have Familiy Sharing enabled in his iCloud)
- UK ID immediate set up a new Family Sharing in UK ID's iCloud, using a UK payment card
- UK ID invited the Child again
- Adult accepted, so that Child moved to UK ID's Family Sharing
- Adult stopped Family Sharing on her iCloud
- UK ID invited Adult to join UK ID's Familiy Sharing
There then was another issue:
Apparently, if only ONE member of Family Sharing has a Country other than the Organiser, NONE can join Apple Music! My Child also had a US account, so neither Adult nor Child could join Apple Music under the Family Share. The only way to fix this is to go into Child's iPod/iPhone, go to her account in Apple Music, iCloud, and iTunes Store and in one of those, you will be able to change the Country to UK. ALL member accounts, and the Payment Method account have to be set to the same Country.