Okay now I get what you guys were talking about when you said the combat feels off. It's the balancing of enemies that is really making the combat feel like that.
It's like they added instant style switching and then they realized that "shit, now the game is gonna be a cakewalk, what should we do?" and the things that they came up with ended-up just being mostly frustrating.
Enemies now punch/kick right through your combo. Even when you are attacking a normal punk, at times they just snap out of your combo and start attacking you back, without much (if any) visual indication. This gets extremely frustrating when you are surrounded by a lot of people.
Besides enemies snapping out of your combos, they are now much more active in defense situations as well. A lot of times you will have problem landing a clean hit since either they are keeping very very competent guards that won't break easily (and even when they do, by the time you have recovered from your attack animation, they are probably regained their guard, or worse they are attacking you) or they are just evading all over the place. In some situations when there are many enemies around you, they'll just surround and stun-lock you into combos from all sides at the same time which could quickly result in your death.
The window of opportunity for preforming a heat move has been made smaller too. You are sure that you are gonna do a heat move but just as you press the triangle button, the window for using that move has been closed. This was never problem in Y0 since the game was balanced much better.
And the sub-bosses with Kiwami heat moves, while may seem like a good idea on paper, are more like a headache in execution. They just get really repetitive and frustrating later on, when you encounter them over and over again.
Now add to all of that, the fact that they've made enemies much more aggressive and it's no wonder that the game just feels off.
The thing that happened with this game, is that Zero was clearly made and balanced around giving you the ability to almost finish the game with just using one style (think DMC3). With Kiwami they added the ability to switch between styles instantly (think DMC4), but the combat and enemies of Zero clearly weren't made with that system in mind (imagine throwing DMC3 enemies into DMC4), so they had to make them tougher and they choose to do it in ways that makes the combat feel unfair.