Secondary account disabled

Hello, my secondary account, that i borrowed to my son, has been disabled.
I just need info about his behaviour. And if his account can be restored.
His nickname is GX TOM. He played from an old huawei mate 2 phone.
He is 8, so i don’t think he did something wrong ingame, or offended someone, also because his account was private and he does not chat (usually).
Thanks in advance.