Maximus XI Hero blank screen when starting games

[Bumble B]

Right then I've just built a i9 rig with the ASUS Maximus XI Hero motherboard and having some major issues when trying to play Elite Dangerous and Dirt Rally

I currently have my Asus GFX 970 as I'm currently waiting on prices of RTX 2080Ti to come down alittle or to get more funds together.

Seems as soon as I run Elite Dangerous or Dirty Rally the display card acts as if i have unplugged monitor cable and shuts off the screen but audio is still going.

It has gonna past the initial start of the game, loading graphics settings etc which take a little while but as soon as the game switches to its proper resolution it goes blank.

I've checked all cables, used an old 480 which this system seems to be ok with.

I have noticed that when the screen goes blank I can unplug the monitor cable and plug into the onboard Graphics port of the Hero and the screen comes back but i have DISABLED the onboard gfx port in bios but still seems to be active.

Also noticed in Windows 10 Pro notifications that I get an error saying "Display driver failed to start Display driver failed to start; using Microsoft Basic Display Driver instead. Check Windows for a newer display driver" I've got the latest windows 10 Pro, latest drivers for NVida but the problem still happens.

I'm abit of a noob with pc building so I'm completely lost as to what is wrong or what I have missed. Could there be a issue with drivers in Windows or NVIDA or something else completely? maybe Direct X12?

[mdzcpa]

Do any other games run? I ask because you only list these 2 in your post.