3d Lights turns 3d model blank

It looks like the issue with your .OBJ model turning flat when the Subdivision (sbpar) mesh is applied is likely due to normals or material smoothing getting overridden by the subdivided geometry. Check that your model’s normals are correctly set and that the material isn’t set to flat shading.

Also, some render engines need recalculating normals or applying the subdivision modifier after confirming that smooth shading is on. Turning off the sbpar restores 3D details because the subdivision isn’t interfering with the base geometry

I’ve seen this happen with Elment3D, so it might be the same with native AE 3D.  When it’s happened to me, I believe the cause is the GPU cannot quite manage the 3D so processes the outline but is unable to process the texturing.  Is it possible to reduce the texture map sizes?