Ok so not overheating. 
That may be drivers, also may be gfx card failing, being damaged.
Swap monitor cable to different output or even better different type of connector. Sometimes card works bad over HDMI or display port, i had slightly damaged Display port cable, and some games had green noise pixels. So maybe something like that causes some problems.
Also some years ago my wash machine cause electricity spikes, and those made my PC go BSOD.
And try some unreal games, see if same stuff happens, or it is only in unreal editor. Try some 4.27 editor + project.