DU Header Library - reloads and removes layout?

Kindly refer to this: https://divi.help/threads/cant-edit-the-headers.3326/#post-10856

 

If it didn't work, you will need to contact official Divi support regarding this issue, as it's a conflict between Divi & Wordfence: https://www.elegantthemes.com/members-area/help/

Another thing you could try is: After opening the custom header style in Divi Library, straight away click to edit it in frontend / Visual Builder. And in the Visual Builder, try to go around clicking open module settings, etc & see if there's any popup from Wordfence to whitelist the action. If no Wordfence popup, then try to refresh the Visual Builder page & test again.

Previously there's a member having such issue & going to the Visual Builder somehow will show Wordfence whitelist popup. Hope that it works for your case too. If not, you will need to contact official Divi support about it.