I have a NUC8i7HVK, bought used from Amazon. When I attempt to install Ubuntu on this machine with a bootable USB, the F10 menu lists it as 'Mac OS X'. The F2's list of available boot options lists it as something like 'UEFI: Part 0 Install macOS Mojave'. I think the previous owner has done something with the EFI partition of the device.
I have tried to re-flash the BIOS, update the BIOS, reset the BIOS to factory settings, but none of that changed the above described behavior. Is there a way to completely reset the device to factory default settings? Clear all internal memory it might have like NVRAM? Please help me. Currently this device is just a brick.
You need to boot into the UEFI Shell and then use the bcdedit command to clear the boot menu. Video showing how to do this is available here: https://www.google.com/url?sa=t&source=web&rct=j&url=https://m.youtube.com/watch%3Fv%3D255ltqk7xDM&v.... There are other similar videos there as well.
Hope this hrlps,