This is probably because the name was inappropriate and has been reported. If we find a name that is inappropriate and that it violates our policies, we'll change it to "unnamed". Contact our support staff if this happens, and send us your new username. But make sure that the new username is not inappropriate in any ways. A repeated disregard of our username rules can result in penalties.
⦁ Remember that even if you don't find the username inappropriate, someone else might. But if you highly disagree with us you can contact our support team and we'll take a look in to it.