Third person jump animation interrupts aim animation even though they are on different layers

Hey guys,

I bumped into a problem a few days ago while implementing a jump mechanic with aim animations to my 3rd person shooter game which leads to jittering and weird animations.

I created a default Animation Controller with multiple layers:

The first (Base) layer is mostly used for my lower body movement and the other layers are weapon specific and targeting the upper body movement. I am using an Avatar Mask to tell the layers which parts to use. I think it is a very common approach to handle it this way and everything looks good so far. I can strafe or run while aiming like I intended to do.

Base layer:

Any weapon layer:

Avatar mask:

So I though it might be pretty easy to implement the jump animation on the base layer so that the player can jump and aim at the same time but somehow the jump and fall animations in combination with the aim animation on the upper body are not matching. The player character starts jittering and doing strange movements.

Here a small clip:

It seems to me that while jumping or falling the animation tries to control the bones and ignores the Avatar Mask and this interrupts the aim animation. I tried copying the animation and removing transforms like a hands, arms, spine but it shows no changes.

Do you guys have any idea or do you maybe have an example how to approach this specific mid air aim animation?