Can't scroll over UI on Mobile

Hi, 

I got the following problem : on my test page ( http://remi-lacombe.com/forge/produit/test-product-2/ ), on Mobile, it is impossible to scroll with your fingers when you are over the UI.

However, when I try your examples, like this one : https://fancyproductdesigner.com/product/t-shirt/ , it works, I can scroll with my fingers and move arround. 

Any idea what's wrong ?

I just can't use the plugin like this.

Thanks a lot.