Comment 8 for bug 1904263

Since all the files I looked at are present and updated, I rebooted and it works as expected.

Also linking in adding --no-nvram to grub from this thread: -
https://bugs.launchpad.net/ubuntu/+source/grub2-signed/+bug/1872212

I ran the install line - boot drive is /dev/sda and efi (/dev/sda1) is mounted /boot/efi

root@pinhead:# grub-install --efi-directory=/boot/efi --target=x86_64-efi --no-nvram /dev/sda
Installing for x86_64-efi platform.
Installation finished. No error reported.

....compelted without error and reboots ok, so moving toward something in that area.