For the archives: The problem was exactly as Mizsei_Zolt??n suggested in <https://marc.info/?l=openbsd-misc&m=169446879525920&w=1>: I had mistakenly toggled Fn-Lock. (I normally have it on, and had failed to notice it was off.) Re-toggling that key solve my problems.
Thanks to all who replied (both on- and off-list), -- -- "Jonathan Thornburg [remove -color to reply]" <dr.j.thornb...@gmail-pink.com> currently on the west coast of Canada "Dear everyone who says masks don't work: Please get your next surgery with no one wearing masks. Thank you for your cooperation. -- anon"