Finally I found the answer to your question, and I'm going to share it because maybe it helps somebody in the future:

1.- Enter to admin panel

2.- Stores (left menu)

3.- Product (under attribute section)

4.- Select the attribute you want to edit, for example Manufacturer

5.- Storefront Properties (in the Attribute Information menu on the left)

6.- Look for Used in product listing option and set it to NO

And then you will hide this concrete attribute in the product list. Not very intuitive, but quite easy.

Finally I found the answer to your question, and I'm going to share it because maybe it helps somebody in the future:

1.- Enter to admin panel

2.- Stores (left menu)

3.- Product (under attribute section)

4.- Select the attribute you want to edit, for example Manufacturer

5.- Storefront Properties (in the Attribute Information menu on the left)

6.- Look for Used in product listing option and set it to YES

And then Incase anyone is experiencing the same problem, the problem was the catalog.xml file - items were missing from this.