This is my basic script. (I know the false and true should be switched. I was just testing if it worked.) It's still showing up to me, though, and I'm in that group..
if (player:IsInGroup(3491785) == true) then
game.StarterGui.StatsBar.Visible = false
else
game.StarterGui.StatsBar.Visible = true
end

1 comment
use PlayerGui, not StarterGui