Updating the UEFI dbx to version 217 may result in your system being excluded from booting in UEFI secure-boot mode if your booting software (e.g., grub2) is blacklisted in DBX version 217. Consider updating Ubuntu to a newer version, such as Ubuntu 22.04 LTS or 22.10, before updating the UEFI dbx to minimize security risks.
Always exercise caution when modifying system files and ensure you have backups in case any issues arise during the process.
they want the shim they get trouble with micro$oft firmware
because in 2020 Grub & shim uses keys certificate microsoft ( as all Ubuntu , Debian , etc … ) but not all DE linux ( still with no boot secure with archlinux & endeavoursos or manjaro )
micro$oft invalidate theses keys in 2020 , and this required for all builder motherboard to delivers new version UEFI with new keys and trouble arrived with size & firmware size
Ubuntu & Debian and other need to boot in No Secure boot to update , because with theses olders keys they will be blocked , no boot
In my system UEFI dbx installed is still 276 but it seems released on 20 febrary 2024 then today!
Release date change version don’t !!
And it still need updated to version 371.