what is the serial Number of your motherboard without the last 4 digits? i ask as i want to make sure its not a CPU support issue as the i7-9700k has 2 Variants P0 and R0 and knowing what i asked for will rule out if it is that as it will let me know what BIOS Version is on your Motherboard.
also can you remove the Evga 2060 super and try with just the CPU's Graphics just to rule out it as a issue?
if you take the Evga 2060 super OUT of the Computer and connect to the back of the motherboard does it still do it? i am asking you to do that as its possible the Graphics cards VBIOS is not playing Nice with the motherboard so have you tried that without the Graphics Card in the computer as you seem to be avoiding saying if you have done that?
it may work in another PC but thats of no help to working out if its a Issue of it in that specific motherboard!