The problem isn't that.
It's that no block is on. (its automatically turned on whenever you get to an escape map) The zombies can easily fly through each other
catching up with the humans far too early.
That also makes it impossible for the humans to slow down all of the zombies in time ending up in a mass slaughter, especally if most of the team isn't watching there backs or if someone throws a grenade that lands behind a zombie, it sometimes ends up launching them into the humans more or less ending the round quickly.
Zero, the owner of ibis has never adresses any of the zmods problems so its probably never going to get delt with properly, if anything hes continually made zmod worse.
best thing to do is to vote against going to almost all escape maps whenever the votes come up and if not ask the admin to turn no block off whenever you get to the escape map.
granted it'll end up forcing everyone to learn the map quickly and not block there teammates by typing !ztele when they get stuck and no one seems to like that so they'll be alot of bitching.
The last option is to go over to gungame whenever the server switches over to an escape.