What is the model number of your nuc? I do not believe there were any nucs with a 4th gen processor, right?
So, contact the manufacturer of your device for assistance with their bios.
There is nothing that can be done for you here. You have an asus device, and you must contact asus for support with their bios.
This forum, "Intel® NUCs, Intel® NUC: Boot Issues", is for support of an Intel device known as a NUC.
I wish you luck in resolving your problem. But, you should not edit/delete your posts in a thread as they may help others with the same or similar issues.
And, I wish you luck with your ASUS bios issue and contacting ASUS support.