Ok - are you subject to any remaining rollover with them ?
Smart books will restrict play if they sense a potential for high exposure to a player - even a losing one.
We are fresh off BetWWS playing fast and loose with allowing “losers” to keep hammering away at them (and winning) without stopping their play until it was too late and trying to justify stealing player funds AFTER the fact. Personally - I respect a book that shows the integrity to not try and free roll players.
Now if your subject to a RO - then the limit cut is BS. Otherwise - it’s a badge of honor as a player, accept it and play at books who will extend higher limits and pay you when you win.