'add to cart' button not working for mp_list_global_products php

I'm using the following code on one of my php files to display 5 random products from the stores in my network.

mp_list_global_products( array('per_page' => 5,'order_by' => 'rand', 'text' => 'none') );

The problem I have is that by default this includes "add to cart" buttons for each product which do not work. If you click any 'add to cart' button, it will animate and respond with 'added to cart' however the product never gets added (not even on a page refresh).

Is there a way to get this to work? If not, Is there a way to use the 'buy now' button instead which redirects you to the product's page?