I have been fighting with a bug on the Oculus GO where the the body of the avatar was not loading, it threw many errors related to OpenGL and Textures.
If anyone has this bug, what i did to fix it was force it to not combine meshes editing the OvrAvatar.cs class.
Also set the textures in Avatar/Content/Textures to
1) Read/Write enabled
2) Generate MipMaps
3) Border MipMaps
If anyone has it please comment so we know its not a project specific.