Comment 9 for bug 1776271

Update - a BIOS upgrade fixed this for me. HP Pavilion All-in-One - 23-q199na.
Perhaps this cleared the NVRAM.

sudo apt -f install resulted in:

W: APT had planned for dpkg to do more than it reported back (0 vs 4).
   Affected packages: shim-signed:amd64

and was fixed with a reinstall
sudo apt install --reinstall shim-signed