I agree with them, It is a buggy feature. Also colors management in Divi is very unuseful and unstable. Use preset and find a way to manage the colors by your self. like saving the colors values in notes book.
(in cases you do not know) Also while you are developing the site you have to disable all the features in Performance tab (Divi Options). Aslo clear and disable another feature for CSS in Boulder tab (As I can good remember). Sure stop Caching (if you your using plugin for that).
Good luck with building the site.