Solved
Wrong usage of abilities ME2
Some of abilities can be used when they are not suposed to. For example Concussive Shot can be used on shielded enemy and i dont think that was possible in vanilla me2.
You can use all abilities on all enemies, they just aren't supposed to do much to them. You may get a stagger and some damage to the shield but it shouldn't knock them down. Same for Warp, throw, pull and singularity for an Adept, they will stagger a second, and lose some shield(very minor usually) and the fight continues. Now if CS is knocking people off their feet that are shielded or Armored, then yeah, that is a bug, but otherwise, just being able to use the power isn't.
