Thanks for all the replies. I was assuming this was the case and also agree it has started to be more common in the last few years. I figured it would be good info for everyone to be aware of. I would question how it is even legally possible to have a gambler win at the casino and have the winnings confiscated by a middleman, but all countries probably different.
There is no middleman in gambling, not except you are placing bets through someone else’s account which is not legally recognized by the casino or gambling platform and that is usually against the terms of service, should you be found out, then funds and won bets would be confiscated.
It is the casino that confiscate bets and not any third party. At most, what could come from a third party in this case, the game providers is the flagging for suspicion. Which might arise from observed behaviors with similar account from a different casino.