The casino owners and the game owners must have a trick in their hands. They will give a part of their profit to a gambler so easily, but it is not that easy. Especially, in some secret places where there is less police or legal trouble, the casino owners reach their own decisions, who to give the win to, who not to give it to, it is under their own control. In many gambling boards or casinos, a gambler wins, but even after winning, he cannot easily take his money out of the casino. The casino owner puts some goons behind him. So that they can snatch the money he has earned from his hands.
There are different casinos, I know of a case where they didn't want to give a player his winnings in roulette because he made a bet and slightly touched the field of the neighboring cell, this is absurd but they didn't give him his winnings. There are also situations when such casinos won't let you out with a big win until you continue playing and lose some of it. But to avoid this, you don't need to go to such dubious casinos, I understand that not all cities have good casinos, but then it's better to play online than to go to such casinos and then get even more nervous when you can't take what you won with you.