Some layouts built with the Wc Builder (especially the empty cart, thank you & login layout) may lose their styling on the front-end.
This issue is happening because of Divi’s CSS caching mechanism. If the same page has 2 layouts, Divi stores the cached CSS for only one of these layouts.
For example, the cart page is the same as the empty cart page. If you build a layout for the cart page ( when it has products ) and also build another layout for the cart page ( when it’s empty ), Divi only loads the CSS of one of them which breaks the other.
The same for the checkout and the thank you page. And also, the account page and the log in page.
A Workaround
1- Clear Divi’s cache by going to your admin dashboard -> Divi -> Theme Options -> Builder tab -> Advanced tab -> Static CSS File Generation.

Click the clear button and check again.
2- If this didn’t fix the issue, disable that option. This will fix the issue but the modules’ styles will be loaded inline.
3- You may also consider using a dedicated caching plugin that will take care of that far better than Divi. Autoptimize plugin is a great example.