Metahuman Auto Face Rigging Error

Hey everyone! So I’ve been messing with Metahuman and the “Conform” feature. I’ve created characters where I wrapped the Metahuman mesh to a stylized sculpt, separated the head and body, transferred vertex order, and brought in. I’ve been successful, but one head mesh is giving me trouble. And funny enough I even created a YouTube video going through my process using the 5.6 Preview build and the mesh that’s giving me trouble worked fine then, but now gives me trouble. The body is fine but the Auto Rigging of the face errors out. Below are images of the character and the error I get when I go to build the rig. If I swap out the head with a different mesh, I can build the rig.

I’ve tried re-wrapping the mesh, re-transferring vertex order, and the mesh operates fine as a blendshape in Maya.

If anyone has any ideas what this could be please let me know!