So I'm going for round 100 in Mauer right now and I accidentally repaired the barrier on the left side of the power room only to then realise that zombies start the animation to remove the barrier but quickly stop and just stand there. I'm using it as a way to get my ring of fire back when I don't have a War Machine but I'm curious, does anyone know why this happens? I haven't seen any videos on it and so I just thought I'd ask! If I had to guess, it's because they're super sprinting at the barrier and too many zombies clump together?