After a couple months of using the processor and having the same problem I accidentally got it to boot with the boot screen and bios access. I am using a 1080ti and have dual monitors. While in windows with the computer running I unplugged both display port cables and switched them(I had my 1 monitor plugged into port 2 and my 2 plugged into port 1 so I switched it to 1-1 and 2-2). To be clear, the computer was running and in windows and I unplugged both cables from the gpu itself. When the computer booted next the bios was on screen 2. I was then able to OC my cpu and ram through bios.