Hi carlucci
I will explain a bit here: in this Articles Categories module, when you enable to show sub-categories, it will show the sub-categories if a category has child category. It will not show the number of item of sub-category - in the parent category.
With the attached screenshot above, I did not mean the drill down, I mean the number of item - next to the category name. As you can see that this module will show the number of article of its own category only, not its sub-category. The 'Hanoi 2' category doesn't have any article so it shows '0' there. The same with Mariscos/pescados/ categories on your site. That's why when you configure to show from the main category, these Mariscos / Pescados show '0 Listing'.
Its default feature of this module in Joomla 🙂
I hope this makes senses.