Hello, and thanks for the prompt reply. If you visit
www.onk.com.ve/index.php/categorias
from a mobile phone, you will see the login section and the cart directly below it after you sign in with username Phillip and password hika1234 (also administrator)
However if you activate the show modules parameter (
www.onk.com.ve/index.php/categorias?tp=1
) you will see that the module is there. However, if you press a link you'll get a weird result.
Looking around I found that the categories listing module is assigned only three columns for small and extra-small device viewing, while the other modules get twelve, but I have not found the setting to modify that.