Family shared organizer
How do I change the organizer from my son back to me?
iPhone XR, iOS 12
How do I change the organizer from my son back to me?
iPhone XR, iOS 12
Do both you and your son have different Apple IDs? If so, I don't believe you can change who the family organizer is as it tied to their Apple ID. He can disband the Family Group, and then, you can create one with your ID.
Ref:
Do both you and your son have different Apple IDs? If so, I don't believe you can change who the family organizer is as it tied to their Apple ID. He can disband the Family Group, and then, you can create one with your ID.
Ref:
Family shared organizer