"Not enough content" I didn't understand why

I recently sent a package for approval that included 20 static mesh models of 3D electrical and electronic objects including some very simple materials to use as an example, a low price “7 $” pack in the prop store, all objects have UV mapping, complex collision, slots for various materials, the quality of the models was good, medium poly relative to the size of the objects, and all had 64 light map resolution, I followed all the mandatory protocols in the manual to send the package. But every time I send it, it gets rejected, with an email saying it didn’t have enough content to send to the store. But I was wondering if it is related to the amount of content or relevance for acceptance, as I see packages with only 1 object in the store. Any idea? What am I doing wrong?