EDIT: Nevermind, looked to be a driver issue and got it resolved quickly.
So, recently in Blender 2.9 I've run into this issue where I cant see the characters materials render at all in any of the shaders in either eevee or cycles. I've tried to reset the materials like I would to fix things like the eyes/eyelashes but it hasn't been working. Was wondering if anyone else has run into this issue and have found ways to fix it?