I'll even wager there is something buried in terms of service that user names need to be inoffensive or something to that effect.
I always thought that a "M Daddy" was an inoffensive moniker for "a cool dude." Little did I know that the OPs current user name might not pass that inoffensive test in the eyes of some:
https://whitneylawgroup.com/alleged-...se-to-proceed/
So good luck with the new name.. itis all but impossible in this day and time to avoid offending everyone.