Try restoring the Secure Boot keys to factory defaults in BIOS and make sure you're booting in UEFI mode with GPT. Also check for BIOS updates and repair the Windows bootloader if needed. A corrupted or unsigned bootloader is often the cause of this ...
You could try contacting ASUS Australia or a local reseller to see if they can order a single BQ16 unit, even though it isn't listed as a retail package. The 2-pack can also be expanded with another compatible AiMesh unit, so a reseller may be able t...