casino says my flat betting looked like bonus clearing pattern

Got a notice from a casino after a few days of pretty standard flat betting on blackjack. They flagged my play and claimed it “resembled bonus clearing patterns” which sounds like code for “we just don’t like your action.” I wasn’t even pushing big amounts or mixing up huge upswings, just trying to stay steady for a bit and avoid rollercoaster bankroll swings.

Has anyone else had a legit issue with being flagged for just disciplined, stable bets? Is this a thing now with more casinos, or did I just get unlucky?