Add additive Pose on Animation

Hey there,

I have an animation montage set up and I need to put an additive pose on top of it to weigh it in and out by a float parameter at runtime. I made a Pose and converted it to additive with the Ref Pose as Base.
My AnimGraph looks like this:

114193-addpose.png

Now when I increase Height Blend to anything above 0 the resulting animation is extremely jittery and completely unusable.

I was confused that the pose (unlike additive animations) is not called “Woker_Height_Pose (additive)” on the node, but I definitely set it to additive in the Animation tab.

Can you explain to me where I went wrong, or what might cause this issue?