Certain Krushing Blows don't work. Sub-Zeros Slide Krushing Blow for example doesn't work, while most of his other Krushing Blows work just fine.
I'm a little bit of a pessimist, so I have a hard time not believing that this wasn't deliberate. Sub-Zeros Slide Krushing Blow is super easy to get. And that one doesn't work, which forces you to use his other, more situational ones... for which you also have to use consumables (for example armor to get those punish / kounter Krushing Blows). And that results in a longer grind. Ehh.
But then again, there are also some brutalities, which don't work in the Gauntlet, where you need to perform Brutalities on the opponents to proceed. So, the game is quite buggy. It was clearly rushed for whatever reason.