Board Thread:Technical Updates/@comment-24006128-20200430205522/@comment-9605025-20200504020950

It is hard to say without knowing what your CSS is. That said, CSS shouldn't be impacting the function of the editor. Perhaps what you are experiencing is the same thing mentioned here? In that case, I don't think it has anything to do with CSS. - Edit:

FYI, since I don't see it previously mentioned:

UCP wikis appear to not use Wikia.css. I have not checked every old CSS pagename but given that Wikia.css is still in wide use on legacy wikis, I thought this would be a relevant thing to note.