Are all three installed in the same mode, either legacy, or UEFI? If one is different, handling the difference can be a challenge.
This may be helpful. All my systems, except a rarely used laptop, are multiboot.
Are all three installed in the same mode, either legacy, or UEFI? If one is different, handling the difference can be a challenge.
This may be helpful. All my systems, except a rarely used laptop, are multiboot.