blackjack cashout got held because provider review says “round integrity check”

was cashing out some blackjack wins and the site flagged my withdrawal for what they called a “round integrity check.” never saw that one before. usually if i get held up it’s the classic id check or bonus stuff. i didn’t do anything weird at the table, just stuck to my usual basic strategy. starting to wonder if they flag you just for winning a few hands in a row or if there’s something else.

anyone had this happen or know what actually triggers a “round integrity check” for blackjack?