You don't need to downgrade, you just need to copy ubuntu/grubx64.efi to Boot/bootx64.efi, which is what boot-repair did before. You can either run it again or manually copy the file.
You don't need to downgrade, you just need to copy ubuntu/grubx64.efi to Boot/bootx64.efi, which is what boot-repair did before. You can either run it again or manually copy the file.