zf_hideout Only leap scouts can get across, and unless people are paying attention it is possible to die before the round begins.
zf_yard: zombies can destroy the barricades keeping them in much quicker than the setup gives, gotta be ready on red team before the round starts
zf_fortress: same for leap scouts, but they're rarely successful on this map
zf_compound_b5: no barricades in this one, zombies can immediately leave spawn during setup and attack
I feel as though it's part of the map and aren't glitches. Usually due to poor design unless they were never designed with the perks in mind.