3440x1440 Ultrawide resolution flickers screen on and off to black about every 10 seconds. I am able to workaround it by switching the resolution to 1920x1080. This has never been an issue before with this game.
Not having seen this bug reported by anyone else yet and not knowing too much about your config, I can only offer some suggestions as what to try next:
Does changing the in-game graphics settings make any difference? I.e. drop them to very low or disabled
Same question regarding vsync or framerate limiting - does it have any influence over the flickering?
Have you made sure to verify the game files if you are using Steam?
Is there any indication in your windows logs of a problem with the graphics drivers. If you generate a dxdiag file, look at the end in the diagnostic section…