Feedback What's wrong with my submission?

So I submitted a few assets on the asset-store and got rejected with the following message:

This is the asset on Sketchfab:

The only thing I see that might cause the issue is that I have a single Albedo texture and the guidelines state:

I am not claiming to be PBR. Just using the Standard shader for the material.

Some screenshots to help looking into the issue:











Any insight would be helpful.

Thanks in advance!