[Plugin: Woocommerce – excelling eCommerce] Variable Products Mobile Issue

Hi all! My website is boydnursery.net.

I’m having trouble understanding and solving a bug with the mobile view of my woocommerce shop within my site. I am operating on the Frontier theme and my simple products within my shop all display fine. When I attempt to checkout with a variable product, the add to cart button does not appear after selecting an option from the menu. This mobile issue exists across all browsers. I believe it may have something to do with the responsive code of my theme, but I would not know specifically where and what to look for. Any help would be appreciated immensely. ??