So it took a re-read to figure out that you were saying I had a USB port directly on my motherboard inside the case. I used Rufus to create a bootable USB drive and plugged it in directly to the server, which failed with the exact same screen.Why make things so complicated for yourself...install it onto a wee USB stick on your PC and then boot the server from that on the internal USB port
Now while I agree that there are a gazillion ways to go about this, most of which work out fine, until you work out the kinks, keep it simple