there are several reasons the platform refuses to pay to gamblers who get big wins, such as whether the user has committed a violation that has been written in the gambling rules. or there are some absolute reasons that have been determined by the gambling platform.
but what i do know is that if a gambler gambles on a gambling platform that has a good reputation and the gambler doesn't break the rules or cheat while gambling, chances are there won't be any problems such as big wins not being paid or being rejected.
so the question you say may still have other question marks such as refusal for what reason. because the platform must have a reason to refuse payment