I modified the axis inputs limiting the saturation and it's still affected.
My current settings for X roll axis are Saturation X 100, Saturation Y 56 and 26 on the curves.
After looking in the recordings and messing around with it more, it seems to happen when going from a left > 60° bank to a right > 60° bank. In that right bank, the huey pitches up about 20° so forward pressure is needed to keep level. I think in this forward input is when the rotor separation is happening. Maybe with this forward input, it's thinking there's negative Gs on the mast or something
I'll work on posting another video and track.