Avatar failing with believe bad transparencies

Having an issue with most avatars from SketchFab not appearing correctly, with what looks like bad transparencies, that is, some parts that should be showing, like the face, are replaced by the hair behind it:

Here is partial fail from a different angle (the hair is not supposed to be in front):

This occurred in A-Frame also - some models were OK through version 1.0.4, then failed after that, and fail in Three JS at least as far back as version 0.119.0. Here is the working version of this particular model, using A-Frame 1.0.4:

SketchFab wrote back: “…viewers/engines like Unity and Three.js (which A-Frame and the glTF Viewer are based on) limit the number of vertex attributes per mesh to 16, which can be problematic for morph animations, which these models have”

Tried traversing the gltf to set all meshes to 100% opacity, that just made a different, still bad, view.

Should I work on getting or making better or different models (found one that works so far) or making changes in the code to better accommodate off-the-shelf avatars, if that’s even possible?
Thank you in advance for your help.