Elementor

This plugin is independent of the page builder. The former checkout page will not be shown as one form anymore, but it will changed into a form with several steps.

On the “WP Admin -> Pages” page you need to find a page marked as “Checkout Page”, as in this screenshot. That is the default WooCommerce checkout page before installing the multi-step checkout plugin and that same page is transformed afterwards into a multi-step form. Elementor has nothing to do with it.

If you don’t find any page that is marked as “Checkout Page”, then you’ll need to click the “Create pages” button next to the “Create default WooCommerce pages” option on the “WP Admin -> WooCommerce -> Status -> Tools” page.