I have AMD Radeon RX 5700 XT. A couple days ago, I was playing Cities Skylines and out of know where my screen flashed all green, then to black and then my monitor shown No Input or No Signal. The only way I'm able to bypass it is to turn off the PC via tower (which I absolutely hate to do, I feel like it's bad for your PC for some reason). I would try to plug the PC into another monitor during this and it would display the same thing. This has happened countless of times. I had another issue that happened twice. Which was, I would be playing Cities and the screen will just go black and take me to my desktop. Cities was still running and my cursor was still the Cities cursor. I had to run task manager to close it. Another issue I had that only happened once was that I was running the same game and my screen went to straight black, but i was able to hear the audio. So, i unplugged my HDMI and plugged it into another monitor. The picture and audio worked perfectly. So for poops and giggles, I plugged the HDMI back into my new monitor and boom, everything was back to normal like nothing ever happened! So now I'm conflicted if it's a monitor, cable or port issue of some kind.