@bluedude For a longer term solution I would implement the dhcp policies from the document Sebastian provided. That solution will help you when you have a mix of bios and uefi systems on your campus.
BUT for a test right now, replace undionly.kpxe with snponly.efi then try to pxe boot that troubled target computer. Understand when you move away from the bios boot loader the bios systems will fail to pxe boot. But what we are looking at right now is/does snponly.efi resolve uefi booting on this troubled computer. Once you find out then put back the undionly.kpxe file until you can get the dhcp policies setup. I can tell you they do work because I have them setup in my environment.