Remove option to leave family group from child account

You can remove an account from a family group. The account will still exist, but it won't have the benefits or restrictions it had when it was within the family group. To remove a member from your family group, you must have an adult account, and be the
one who gave consent.

1. 1
   Go to family.microsoft.com.
   
2. 2
   Sign in with your Microsoft account, then:
   • To remove a child, scroll down and select Manage my child's profile info, select the child, select Remove consent for this child's account, and confirm. Then, go back to your family’s page, and under the child’s name, select More
     options > Remove from family, and confirm.
   • To remove a child because they’re now an adult, or if an adult account has been misclassified as a child account, verify the account.
   • To remove an adult, under that person's name, select More options > Remove from family, and confirm.
   • To leave the family group if you’re the only adult in the family, remove all children first, then find your name, select Leave family, and confirm. You must be over the statutory age to remove yourself.
   • If you're incorrectly listed as a child when you're an adult, see How to change a birthdate on a Microsoft account.

What abou the xbox settings itself did y'all try to set preferences that y'all want for his account straight from the xbox?

The problem is this once an account is setup the DOB on the account is set in stone there is no way to change that DOB even if you go into the account and change the DOB it will still be seen as the DOB when the account was originally setup.

It sounds like when the account was setup the DOB was over the age of majority (18 in most countries) which defaulted the account to an adult account so even if you put it into a family as a child account it will still have the capabilities of an adult account
(like removing itself from the family) the only way around this would be to create an account for your child with a DOB under the age of majority and putting it into your family.

Keep in mind any game progress or purchased games would not be able to be transferred over to the new account.

I haven't bothered setting preferences since I know he can easily leave the family

Hi, my name is Marvina and I will be happy to help you.

I'm sorry you have this problem, researching on the internet I was able to find that in the forum, the independent advisor Geri M, recommends the following steps for a solution.

It sounds like you are having trouble removing a child from a family group and at the same time you as the organizer.

Let us check this together and resolve it to help your concern.

To remove a child from a family group, you must:

Click Manage my child's profile information and find your family member.

Select Remove consent for this child's account.

Return to the family group.

Click More options below the family member you want to remove from your family group.

Select Remove from family group > Remove.

Only family group organizers can remove family members. Leave the family group or remove members - Microsoft Support.

Information source (credits):
https://answers.microsoft.com/thread/236c76f7-8cfb-4499-9b6f-676d1238f279

Best regards,
Marvina.