I contacted wetsuit, but I still haven't received an answer. I then did a small deposit and my Free BTC base prize was fixed and is back to normal now. I think that there might be a new formula that determines the base prize for an account and if your current balance is lower than your total earnings (free rolls + referral earnings), which may happen when you make a withdrawal, then your base prize is halved. This is just a wild guess, so let's hope that one of the Freebitco admins tells us whether this is the case or it is something else.

Are all of you who had their base prize halved made a withdrawal? Is there anyone who have never made a withdrawal but his base prize got halved anyway?