Cannot add Child to the Family. Process flips over at the last step.

For 4 days I am trying to create a child account with no success. I am doing so on two devices MacBook Air / Sonoma 14.4.1 (parent's device) and MacBook Big Sur 11.7.10 (child's device).

I've purchased and activated iCloud+.

Verify age with touch ID and credit card control no.

provide name, date of birth, creates Apple ID, password,

go through accepting t&C

to get this message at the last stage...

Which means... during new apple id creation the problem appeared. at the moment we cannot create your account.

please help!

[Edited by Moderator]