Im wondering how I can play in the same lobbies as i could before. What I mean is before i beat the game with my amazon i could play in "A" lobbies. After I beat it with my amazon it only shows me "b" lobbies now. Im very confused because I see people in "A" lobbies making cow portals and you can only do that after youve beaten the game. I tried just making a normal level game lobby but it doesnt show up in the "A" lobby list. I just want to play in the "A" lobbies again with people who havent beaten the game. How do I do this?

oh and i dont have the expansion and never have had it.