to find the culprit: a botched update had flagged the boot sector as inactive. A few clicks later, the UEFI boot entries were restored. The Resurrection
dism /Mount-Image /ImageFile:"C:\DLC_ISO_Project\media\sources\boot.wim" /index:1 /MountDir:"C:\DLC_ISO_Project\mount" dism /Add-Driver /Image:"C:\DLC_ISO_Project\mount" /Driver:"C:\DLC_ISO_Project\media\DLC_Drivers" /Recurse /ForceUnsigned dism /Commit-Image /Unmount-Image /MountDir:"C:\DLC_ISO_Project\mount" dlc boot uefi iso
Ensure the "USB Device" is moved to the top of the boot priority list in your firmware settings. CSM/Legacy Mode: to find the culprit: a botched update had