I knew, I had received a welcome bonus but didn't know about the requirements until I was about to make the withdrawal, a pop message warmed me that I was going to lose the bonus if I decided to proceed with the withdrawal. I didn't mind. I lost it but withdrew my winnings
You’re lucky that you only lose the bonus amount because some casino usually deducts all the profit made during the time when bonus is active.
So can only withdraw your bankroll in the end. New casino usually have this feature and I lose a lot that was supposed to be profit because of this BS rules on casino bonuses that is not clearly indicated on bonus ToS.