Responsive Trigger

I’ve been having trouble with my WooCommerce store for a few weeks. It’s been super buggy. The latest issue is that the hamburger menu (responsive on mobile) isn’t working on the product pages, but seems to be fully functional on every other page.

What could it possibly be?
Thanks!

running: WordPress 4.8.4, WooCommerce 3.2.5, Neuva Theme

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