I have a simple COP network with a PreviewMaterial set. When rendered with Karma XPU it looks like this:

But when simply rendered in the viewport it looks like this:

I see two main issues here:
1. The shading looks really ugly
2. The square black area on the foundation of the model looks off, meaning it looks Houdini tries to apply some smoothing to the foundation, but instead of looking like a sharp 3d box it ends up looking this smooth.

What am I doing wrong?

Thank you in advance and best regards