Tips for using the pile bunker/ melee in general?

Idk what I’m doing wrong, it seems like I always miss my melee attacks in general and then I get punished while stuck in the animation. The only melee weapons I can use reliably are the pulse sword and lance. Even when I get a stagger it seems like they are able to always dodge or I seem to somehow just miss the hit box!

Can someone who’s good with the melee weapons pls give me some tips? Thanks!