The update to the LibreWolf port is pretty nice, and it seems to be more stable and less prone to spinnng up the laptop fans.
So that’s nice. 
But keyboard control of the browser seems to be disabled somehow. ALT-left arrow for back doesn’t work anymore, nor do the arrow keys for scrolling or the PgUp and PgDn keys.
Has anyone else experienced this?
Huh. ALT-T for new tab does still work.
EDIT: Ooooh, of course. Keyboard commands that are tied to menu items still work.
Ugh.
So: some of it just spontaneously came back on its own. Arrow keys and page up/down, specifically.
And back is apparently now CTRL-left, which I have Shortcuts mapping to something else.
So whatever the hell happened in LibreWolf this morning maybe wasn’t actually the port’s fault.
Oooh, neat: you can go to “about:keyboard” and fix that.
OK; I’mma shut up about this now, since the main glitch doesn’t seem to be happening anymore and no one else has said it happened to them.