Any explanation of why the arm disappears when warping it in Adobe Animate?

Hello Guys,

I am having an issue when warping in Adobe Animate.

First, the arm disappears when creating a warp rig, 

and Second, it deforms a lot when creating a warp rig.

I made it so it does not convert it to bitmap when warping due to quality issues,

but is there any way to fix the issue with assets deforming or disappearing when creating warp rigs,  without having to convert to bitmap?

I have an mp4 file of the issue