So I'm having a weird issue with having two displays set up. I have my BenQ XL2420T on DisplayPort and my 4K Vizio TV on HDMI 2.0. It hasn't had this issue before, so I'm thinking it might be the drivers, I just haven't got the chance to test it yet.
 
Basically if I have both plugged in and am on the TV, even when I have the monitor disabled, the TV will randomly lose signal every minute or so. Also, every time I go into a game it will flicker like it's trying to change resolution and then give me a black screen.
 
The issue doesn't happen on the BenQ, and interestingly enough, it doesn't happen when I have the BenQ unplugged. 
 
I'm on the newest drivers and have never had this issue before. Tried a different HDMI cable just to make sure, and it still does it. Could it be a software issue? 

You should try rolling back to a previous version of the drivers. Reinstall the card's drivers using DDU (display driver uninstaller), which is software that will wipe the current Nvidia drivers from the system. You should run it again and select "AMD" a second time around if you've ever had one of their cards installed in your system. Download the latest drivers from geforce.com/drivers, select "Custom installation" and check the "Perform clean installation" box at the bottom of the installer. It seems like it could be driver related since you didn't have this issue previously. Let us know if this makes any difference. 
 

So I found something interesting. It's a minor inconvenience compared to my last situation being completely unusable. Apparently if I have both displays on and extended, it works fine. It's only when the DP and HDMI are connected and the DP monitor is off (Show only on display 2) that the issue happens. This is on the newest drivers too, so apparently it's been an issue like that all along. Any idea what could be causing this?