If enabled Divi maintains a cache of many pre-compiled CSS assets.

When you move the site to another URL the cached CSS has the old URL embedded and you will notice many weird formatting issues caused by missing style sheets.

You can remove the et-cache directory and it will rebuild itself and re-compile the CSS as follows:

You can achieve the same result from the Divi GUI goto:

Divi => Theme Options => Builder => Advanced => Static CSS Generation => Clear