On Dragor Primaris the title of the mission was spoils of war. 

when i was doing the mission enemy would fall tru the floore and die when you are fighting on high elevasion area also if the enemy is on higher elivation shooting you and try to shoot them back your shot would pass tru or mybe go over there head even worst if the enemy is on higher elivation and they have not spoted you yet when you try to shoot them you cant also same goes the other way around if you are on higher elivation and they are on lower elivation and you try shooting them your shot will hit an invisible Wall  LOL or even when you are standing on the edge of the higher elivation your shot will just hit and inivisible wall :( when you are trying to shot an enemy that is on the lower elivation. 

I hope what i said make sense i have the vid of the bug if u want me to pose it on youbute i will but i will ask for permission 1st before i do some thing like that. :)