Mixing physics and animation

I'm trying to make so my character has ragdoll arms. I was able to achieve that if I only had a walking animation with a mask for the legs. Then I want my character to play a melee hit animation only from spine02 above so I made a layer called "Arms", added a mask for the arms and set it to override. The problem is: when I add a state to the Arms layer containing an animation for the arms (even with the layer AND the animation masked) the arms won't act as ragdoll anymore, even when the clip is not playing. How do I fix that? Here are some screenshots:

Spoiler: Arms layer

Spoiler: Legs layer

Spoiler: The masks

Spoiler: How it is

Spoiler: How it should be

Here I removed the attack state in the animator so you could see how it should be.

I might be missing something really simple. Thanks for any help!

 

I just found out that if you set 'motion' to none on the Attack state, start the game and then set 'motion' to the hit animation it will work as expected. Looks like a bug... Still not a fix though, I really don't want to write a script just for that.

 

What about making the layer additive?

 

Already tried it. Nothing changed.