Hi Miguel,
I think I uderstand now. So when you search for product categories, and the plugin returns them, it redirects to a 404 page.
Unfortunately, that is not related to the plugin, as the category URLs are returned by wordpress itself. The plugin just displays the links.
For example, try clicking on this category on the product you linked: https://i.imgur.com/MPkXDPL.png
It will lead to a 404 page: https://luaterra.com/categoria/salud-sexual/fertilidad/hombre/
Similar thing happens with some of the product ‘Etiquetas’. For example, on this product, if you click this item: https://i.imgur.com/Ul7XEu6.png
That also leads to an empty page.
This usually happens when the permalink structure is configured incorrectly on the back-end. If you have any plugin active that may change the permalinks, or affect the products page, that could also explain that.