I got this error when running the upgrade on 2021-05-02 as proposed by the system:
grub-efi-amd64-signed:
Depends: grub2-common (>= 2.02~beta2-36ubuntu3.31) but 2.04-1ubuntu26.11 is to be installed
I used:
apt list --upgradable to get list of packages that needed to be upgraded:
Listing... Done
grub-common/focal-updates 2.04-1ubuntu26.11 amd64 [upgradable from: 2.04-1ubuntu26.9]
grub-efi-amd64-bin/focal-updates 2.04-1ubuntu44 amd64 [upgradable from: 2.04-1ubuntu26.9]
grub-efi-amd64-signed/focal-updates 1.167+2.04-1ubuntu44 amd64 [upgradable from: 1.142.11+2.04-1ubuntu26.9]
grub-efi-amd64/focal-updates 2.04-1ubuntu44 amd64 [upgradable from: 2.04-1ubuntu26.9]
grub-efi/focal-updates 2.04-1ubuntu26.11 amd64 [upgradable from: 2.04-1ubuntu26.9]
grub2-common/focal-updates 2.04-1ubuntu26.11 amd64 [upgradable from: 2.04-1ubuntu26.9]
And
sudo apt --only-upgrade install grub-common
Updated that package updated everything