I am using WooCommerce add to cart URLs to build a direct checkout widget on a client's homepage. I thought I had everything working well, but for some reason when they click the direct checkout links, it adds three products to their cart instead of one. I disabled all plugins except for WooCommerce and the site-specific plugin which generates the widget. The same issue happens when you simply enter the link manually into the address bar.
The development site is rlmarts.staging.wpengine.com
Any insight into why this might be occuring?