Dear David,
I have the same problem! I have already purged the cache and opened the site inside an incognito-window. The views still look different.
The problem is that the customize-view looks correct, but the normal view looks completely broken, it also does not react when I change something inside Elements. But I can see in the customize-view that the changes have been implemented. They just aren’t visible in the normal view!
I appreciate your help.
Thank you very much!!