Since the 1.5 update on pc, it seems that I cannot perfom any melee finisher. I've looked at videos, forum and wikis on how to do them and it doesn't change a thing. I know that you have to use a charged attack on a low hp enemy so the attack kills him but it just doesn't work. The perk Hidden Dragon works fine btw even with gorrial arm or mantis blade.
Is there some sort of perk that I need to perform them ?