How to prevent custom normal artifacts with morph targets?

How normals should look,



How normals look with morph targets. (look at the mouth)

Is there anything that can be done about this? I’ve seen it be solved with recomputing tangents, but that causes all custom normal data to be lost. Is there any way to use skeletal mesh morph targets and keep custom normals?

By looking at Model it seems like it does not rely too much on Normal. Can you try disabling Tangent Space Normal in Material Settings


See if it helps.

Makes no difference sadly. The normals are from the mesh not a normal map, if that matters at all.