Weird mixamo animations

I have a character I downloaded from Mixamo with animations. I then got a gun off the asset store. The thing was, the gun didn’t fit properly into the characters hand. So I attached the gun to the right hand ( Where the trigger is ) and use SetIKPosition() and those functions to have the left hand follow the barrel of the gun. But only when I’m using the animations from mixamo the left-hand fingers mesh is messed up. The fingers are pointing in every direction, but I’m not sure if they are stretched.

Found out that when you download animations from mixamo, make sure to go through all animations ( I selected and changed all at one time ) and under rig change Avatar Definition from Create from this model to Copy from other avatar and choose the T-Pose avatar or whatever you have as a base.

Well, when I change avatar def., my animation is messed up…