sudo efibootmgr -c -L "Windows Boot Manager" -l "EFIubuntushimx64.efi"

#Mount efi partition. check which partition is FAT32 with boot flag. Often sda1 or sda2 but varies.
mount /dev/sda1 /mnt
#only if not already existing,
mkdir /mnt/EFI/Boot
cp /mnt/EFI/ubuntu/* /mnt/EFI/Boot
# If new folder created, the bootx64.efi will not exist, skip this command
mv /mnt/EFI/Boot/bootx64.efi /mnt/EFI/Boot/bootx64.efi.backup
# make grub be hard drive boot entry in UEFI. If not existing, may have to update UEFI also with efibootmgr.
mv /mnt/EFI/Boot/grubx64.efi /mnt/EFI/Boot/bootx64.efi