I added metal materials to my model in blender using principled bsdf shader. it looked fine in the rendered view. I exported to a .dae file and copied to Xcode following the steps in this post. when I run the app I just get a plain white model. The materials are in the hierarchy but its's not on the model.
Xcode also doesn't preview the model. I'm not sure why it's doing this but this is also happening for the included default 3D model. So if anyone knows how to fix this in addition please let me know.

