Buy Button not working on Prosite

I am hoping to sell some prints through my Behance Prosite.

I am in the planning/testing stages and am finding that although the Buy Buttons work on my Behance portfolio page, they do not work on my Behance Prosite.

On the portfolio page, the popup box appears, but on the Prosite clicking the button does nothing.

Here is an example of my portfolio page (where the buttons work):
And here are the same prints for sale on my Prosite page:

Any suggestions? I'm anxious to start using your services
1 person has
this problem