Referring to UEFI settings as BIOS is confusing because many UEFI implementations have a CSM that emulates legacy BIOS. I'm assuming the OP means they can't get into UEFI settings to configure UEFI, rather than being unable to boot (legacy) OS's in CSM-BIOS mode?
Has the drive either been sufficiently wiped to remove the EFI System partition, or have superfluous folders (Ubuntu or GRUB) been removed from the EFI System partition?
Referring to UEFI settings as BIOS is confusing because many UEFI implementations have a CSM that emulates legacy BIOS. I'm assuming the OP means they can't get into UEFI settings to configure UEFI, rather than being unable to boot (legacy) OS's in CSM-BIOS mode?
Has the drive either been sufficiently wiped to remove the EFI System partition, or have superfluous folders (Ubuntu or GRUB) been removed from the EFI System partition?