The WooCommerce Thank You Page Customizer is not working properly

I tested the free version of this plugin. My woocommerce is using Flatsome theme, which is a very popular theme. And we installed the CheckoutWC plugin as well. When I tried the free version, the layout customised in the backend cannot be displayed correctly on the front end. The texts are misaligned and the table that displays the order details and customer info cannot be shown. The format is a mess.
I want to go premium, but not sure if it’s the same with the premium version.