In the support chat, they wrote to me that I violated the bookmaker's rules, so all my winnings are canceled and that I can only withdraw 150 dollars. It seems that the bookmaker considered my first lost bet normal, and did not like the winning bet, very convenient.
All casinos have strict policies regarding any suspicious account activity. It's only natural that problems occur when you win, as there could be manipulation or suspicious activity, especially if you win repeatedly. However, when you lose, it's normal for no one to suspect manipulation or suspicious activity.
Since BK8 Support has promised to look into your issue here, this is a positive point for the service. You have the right to review all the convincing reasons for your account being banned. I hope the issue is resolved soon.