I got an EVGA FTW3 Ultra about a week ago. I haven't had any problems since yesterday, and I'm not even completely sure if what happened is actually a serious problem or not. I've looked at other descriptions of 3080 black screen errors and none that I've found seems to quite match what occurred.
So here's what happened: Yesterday I turned on my computer but didn't do anything else--I just turned it on with the power button, and the monitor was off at the time. Many hours later I powered on the monitor to use the computer, but it wouldn't show me anything. It should've shown me the Windows log-in screen (I'm using Windows 10). The monitor popup box said that the HDMI channel was "Active," but it looked like no video signal was coming through. I rebooted the computer using the restart button. That didn't fix the problem--I still wasn't seeing anything. So I shut off the computer using the power button, then unplugged the HDMI cable from, and plugged it back into, the 3080. Then I booted the computer up with the power button and everything was working correctly. I haven't had any problems since.
Windows Event Viewer didn't register anything that would suggest a video failure. There's nothing in there such as "Display Driver stopped responding," and searching through Event Viewer for "nvidia" and "nvlddmkm" turns up nothing whatsoever.
Is it possible that this was just a transient problem at the monitor end because I took so long to power it on after turning on the PC? I have used the Metro Exodus benchmark at 4K and maxed out to test the stability of the video card a few times. Each time there are no problems and it gets the expected frame rate. Max temperature it hits is 71C and max power draw is about 377W in that benchmark.
I have no OC or other adjustments to the card. I've only run it in "out-of-the-box" condition, currently with 461.09 drivers.