Checkout Page Won’t Activate

Hi there, love the plugin. My only issue is that my Checkout template won’t activate. I’ll click “set default” and save, and it says “active” until the page is refreshed, and the checkout template isn’t reflected in any browser. It just looks like the WooCommerce default. Surely this is me just missing something, but could anyone help me out?

Is the problem that I already have a default checkout page that uses the WooCommerce checkout shortcode? I’m unsure of how that’s supposed to be set up with the ShopEngine plugin.