Could you please check how it works with some default WordPress themes like TwentyTwenty or WooCommerce Storefront to understand if is it our theme issue or not?
In this case, please send me access to the admin panel and confirm the permission for plugins deactivation, and switch to the parent/default theme. As soon as we complete the testing we will enable all back, You would better make the full backup of your site.
In the last update, WooCommerce added the Order Attribution option by default, and some checkout layouts do not work correctly, so to solve this problem you need to either disable this option or add the “Shipping details” element to the Checkout form layout.