Is this using a model made for VSFAvatar or the standard shader like Vroid has?
It's not a model made for VSFAvatar - it's a model from VRoid Studio, edited in Blender and Unity 2019.4.21f1 using UniVRM 0.71.
Just to check, I updated to the latest UniVRM 0.83 and made a new test model - this is one of the VRoid Studio example models, and all I've changed is the face materials, changing the "MToon" shader to the "Standard" shader. These are set to either "Opaque" or "Cutout" rendering. "Standard" shader is a supported shader for VRM models, I know that most people don't use it though!
You can test for yourself using this model:
https://hub.vroid.com/en/characters/8141690519945910041/models/91056800163305760...
Update now available! Thanks for your help! https://oose.itch.io/vtubereflect/devlog/294323/update-to-univrm-v0830