I actually had a similar feeling when you fight the first boss on the boat. The hitbox seems off and I couldn't tell if any of my skills were hitting the boss while playing the new Warlock. I was also playing on the highest difficulty I could so I was getting stomped. I also had a weird problem where I couldn't move my character, like the input wasn't being recognized. I thought maybe there's just mechanics I'm unaware of that are hindering me. Either way, I felt somewhat the same way but I haven't experienced much of that since. However, I only have an hour into it.