How to get 3d Melee attack animation to play right?

So I am trying to implement an melee attack animation that I took from mixamo, in preview it plays right but inside the game when I play the animation players hand doesnt move up correctly.

First I thought it was because of the Inverse Kinematics setup I did for weapon aiming, but then I commented out all the kinematics stuff and it still doesnt play right. Any idea?

video link here