Is Earths Defence Mission Bugged?

[(PSN)CrimsonDemonX]

ok not  so much a rant but more of a question so i was doing an infested outbreak mission on earth the defence mission and spend 30 mins trying to complete 5 waves cuz for some reason they get stuck in the rooms up on the cliffside is there some easy way of getting up there without excalibur super jump or something i tried with ember and it took me 10 mins to wall run up the narrow little space they give to run up im sure u all know what im talking about plz tell of an easy way to get up 2 those rooms