Yes same for me, but I don't class as a UK player at VS.
Can we nail it down to a territory or territories that get the 'We'll steal some of your winnings booster' when actually logged in?
I tagged @Team.Videoslots earlier to get an explanation because it looks rather chaotic with the two versions. It's not even the same for all in the UK when you read the member posts.
Maybe it is connected to the date of registration. Maybe they are just rolling it out. Who knows.
Either way, just having that up there is not right. No casino can withhold any part of your winnings. And calling it a Weekend Booster is misleading as it is your own money you won on the slots. Plus, they do not explain if you hit a payout on a spin that is less than your bet, which means you actually do not have a win. Are they taking it from there too?
While they have a clause in the Weekend Booster part that new players consent to have part of their winnings withheld, there is no such mention in the general casino terms, which new players accept when they register. They do not see the Weekend Booster terms. Neither do the General Terms mention that enrolment is automatic, optional or whatever.
Maybe @ternur could give us his legal opinion.