Help

Is anybody else having trouble increasing their incursion level (or whatever it’s called lol) in the different episodes to unlock the other characters? I don’t play very often so the only character I’ve unlocked is Joker. I’ve been trying to increase my incursion level in the other episodes to unlock the others but it keeps telling me I can’t increase my incursion level in another episode when a current one is active but even when I play that one it tells me I’m under leveled. So when I try to increase it I get the same message.