UV seams on non-uv/texture material

Hello,

Looks like for some reason the UV seams are exposed on a Blender Material node with materials that are not using textures, only primvars to drive the blending and to load the displayColor:

As you can see on the video, if I connect each material directly to the output, the glass and the SSS material looks fine, but as soon as I connect the Blender Material some lines appear on the UV seams but as I mentioned, the material is not using textures on that section.

This is how looks the primvar “bbox” that I’m using to blend both materials:

And here is how it looks with Redshift and Karma in Solaris:

Maybe this is a bug?

You can test the scene with this usd:
ai_pixel_process_apple.ov.v01.usd (38.9 KB)

You will need to download the USD dependancy from here:

I hope that you can find what is causing this.

Thanks.