@clench Turns out that if I reset back from dark mode, I can once again edit bookmarks. So it's a bug. I did report it early last week. Hopefully the developers will notice and address it. I can't believe I'm the only one so affected.
@firstlast I have this problem too. From reading down this list I have discovered that switching to light mode restores the bookmarks visibility in the majority of cases. This is a nuisance and I hope it is addressed in the next "update".