My only sin is being profitable.
Being profitable is not a sin or it should not be considered as a sin.
There are people who won many bets and they are still active playing at sports bet sites. If gambling casino start to ban every winner from thier site, soon people will start giving negative feedback for that sites.
There might be something else which you are doing unintentionally and getting your accounts locked.
I was wondering how often OP Gamble's or does it mean that gambling is the only work he does and puts all efforts, energy and focus on so as to win big and earn a living. If then it is obvious that the casinos OP has identified with has taken note of OP game pattern and would definitely tell when OP is on their platform so therefore it would be very difficult for OP to play with theta same pattern but only if OP change game pattern which I think would be very difficult for OP to do.
The issue of OP to have defaulted the casino in one way or another I do not really think that is the issue because I read a comment here where a poster said that casino do restrict account and that seems to fin too often and I think that is a big challenge and threat to them hence their actions against OP.