To update the birthdate on a profile that was incorrectly entered, you typically need to follow the procedures set by the Microsoft Family Group settings. However, if you are encountering an error message while trying to update it, it may be necessary to contact Microsoft support again for further assistance. They can provide specific guidance based on the error message you are receiving.
If you are unable to remove the profile from your Family Group, this may also require intervention from support, as certain restrictions apply to family accounts, especially for child accounts.
Make sure to provide any error messages or codes to support, as this will help them diagnose the issue more effectively.