Here is my final post on the issue.
All solutions seem to involve greater risks than benefits, given that the old kernel works just fine. Tonight, the final straw happened. The Discover update process updated TWO kernels at the same time. First was 5.15.0-82 (standard Ubuntu LTS), followed closely by 6.2.0-31
On reboot, I was using the Ubuntu kernel; none of the GRUB entries mentioned 6.2.0-31
I credit @skyfishgoo for naming grub_customizer as the source of this puzzle.