Comment 6 for bug 1896608

Hm, so before calling grub_multi_install we check if we have been installed into target as efi with

        if test -e /boot/grub/$target/core.efi; then
          db_get grub2/no_efi_extra_removable
          if [ "$RET" = true ]; then
            NO_EXTRA_REMOVABLE="--no-extra-removable"
          fi
          NO_NVRAM="$(no_nvram_arg)"
          run_grub_multi_install --target="$target" "$NO_EXTRA_REMOVABLE" "$NO_NVRAM"
        fi

so it would seem that /boot/grub/x86_64-efi/core.efi exists, yet user chose not to install grub-efi.