Note that you can verify this issue by downgrading grub-related packages from proposed to updates:
sudo apt-get install shim=0.8-0ubuntu2 shim-signed=1.19~16.04.1+0.8-0ubuntu2 grub-efi-amd64-bin=2.02~beta2-36ubuntu3.2 grub2-common=2.02~beta2-36ubuntu3.2 grub-common=2.02~beta2-36ubuntu3.2 grub-efi-amd64=2.02~beta2-36ubuntu3.2 grub-efi-amd64-signed=1.66.2+2.02~beta2-36ubuntu3.2
Note that you can verify this issue by downgrading grub-related packages from proposed to updates:
sudo apt-get install shim=0.8-0ubuntu2 shim-signed= 1.19~16. 04.1+0. 8-0ubuntu2 grub-efi- amd64-bin= 2.02~beta2- 36ubuntu3. 2 grub2-common= 2.02~beta2- 36ubuntu3. 2 grub-common= 2.02~beta2- 36ubuntu3. 2 grub-efi- amd64=2. 02~beta2- 36ubuntu3. 2 grub-efi- amd64-signed= 1.66.2+ 2.02~beta2- 36ubuntu3. 2