ban

We will need a bit more information for that but as they are your sons and they live in the same house they use the same internet connection. Only one account per internet connection is allowed. If not it is considered as multi accounting which is against the terms of service. Therefor your sons are not allowed to join a game together, which is probably what happened.

i am playing as well on the same net so how come i am not banned ? do you have a discord link so we can talk or you can come in to mine and all 3 of us can talk 4 of us with you

and we have been playing like this for over 3 year

You can submit a support ticket using the link in my signature. We don't discuss such matters in public.