Back to Bookmarks: Recently Bookmarked doesn't even show up. So that resolves that problem.
Judging from my results, I guessed that the update might resolve your issue, but I wonder why your item disappeared unilaterally and mine needed assistance?
If you're running 57.0.4, then that's a puzzler.
I just bookmarked a previously unvisited site and no Recently Bookmarked category showed up under Bookmarks.
Yep, 57.0.4, and I posted a while back that "I just tried adding a new bookmark (More: different page of previously bookmarked site) to see what I could see, and the Recently Bookmarked category didn't reappear."
So far, the only downside of the latest version (Firefox Quantum) is the "TLS handshake" which precedes each and every URL access. Sometimes it 'fails' and I have to hit reload one or more times for it to 'catch'. That may be an issue with my dialup transfer speed, and it's quasi-tolerable. [For example, gaining initial access to FTM took 5 reloads for the TLS handshake to 'catch' and opening up the reply window took only one.] Apparently the "TLS handshake" has been a problem across all platforms ever since it was introduced in version 54; but it would appear that most kinks have been worked out.
I know nothing from "TLS handshake" other than that I'd be
reeeally unhappy having to reload a website 5 times before it would work.
If the problem is pervasive, it negates the speed boost.