Problems with gallery (bridge theme)

Hello there, the plugin works great with products with only one image, but wherever there are more than one it just doesn’t work.

Example of one-image product page:
http://www.sumampa.com/shop/tappeti-antiguos/tappeto-inizio-xx-secolo-24/

Example of multiple-images product page:
http://www.sumampa.com/shop/tappeti-contemporanei/tappeto-contemporaneo/

I am using Bridge theme with woocommerce 3.1.2

Thanks in advance for your help.

The page I need help with: [log in to see the link]