Focal Theme Add To Cart Button Disappearing

[samjbruce]

I have a store running the Focal Theme and we have recently come across a problem with the Add To Cart button. There seems to be no reasoning as to when or why, but the add to cart button disappears on all of our product pages and in the cart drawer at random points throughout the shopping experience. When reloading the page, the Add To Cart button flashes, and then disappears again. Any help would be greatly appreciated.

Link to website: simpsonsmeats.com