Stress test #50-52 the zombies have been really weird, and bizzare in terms of navmesh/pathfinding. You can shoot multiple shots, but they will still go to the first shot you ever fire (ignoring the rest of the bullets you just fired, which they should be alerted to?)
If you are inside a building, they take very long to get inside the building, if chasing after you.
Also, something with being on top of the hills at NWAF (above hangars, etc.) they won't chase you, (even if you spray a full magazine and bullets beside them). It's until you go to the bottom of these hills, where they will then chase after you. Can be very random, but just noticed it happening quite a bit.
(another one, is that there's so many zombies glitched inside of these hills that you can hear? They might run glitch/into these hills and get stucK)