What do you think you did to fix this?
Well there was 2 instances that were wrong on my map, One of which when zombies spawned at my barriers they sometimes just sat there, this was because the hallways that led up to the barriers was off centered... partially touching the barrier itself so the zombies sometimes recognized the barrier and some didnt.
The other instance when I go from zone 2 to zone 3 the zombies would stop chasing, the zones were not touching, I zoomed in on the smallest grid available, and saw it wasnt touching, so i lined them up.... but some zombies still stopped chasing me, sooooo I looked again, my door/buyable barrier was also half in zone 2 and half in zone 3, SO i concluded that the zombies still thought that the door was still "closed/not bought"so thus not realizing that zone 3 was "open" even tho I did buy it thus having some stop chasing me.. shifting the door into zone 2 only, fixed what ever zombies stopped.
SO, make sure zombie barriers arent inside any walls and lined up nicely, and make sure the buyable door from one zone to another is in the active zone AND make sure your zones touch, not inside eachother and not separated with a gap.