Hi
Just render another model, and verified the issue:
Here, an screenshot of the model just generated the obj, without change anything int the MTL file.
Here, an screenshot of the obj file opened in Meshmixer. Left side, with single JPG texture, and right side, exported with multipart jpg texture and replaced in the MTL file the Kd word for Ks word.
please, see 100% size: https://support.capturingreality.com/hc/user_images/fQ3oTzQcObGCj9wpEEGNKA.jpeg
