Unable to send friends requests for < 14 years old

Hello.
My < 14 years old son can't send friends requests on Xbox on FC 25 in EA Game Hub.
he's already playing online, and he already has some friends on Xbox, but now he want to add a Playstation friend  using EA ID.
When he tries to add his friend or someone else using EA ID, he gets the error "Unable to send friend request. Retry".
Is this a restriction or maybe is there something to set in privacy settings ?

Thank you