Wondering if anyone has seen anything like this before.  I noticed it just about the time I installed one of the first 500 series drivers but even after multiple DDU's and reinstalling older drivers I'm still noticing it.  My ultrawide LG 34GN850 will get this weird "screen door" effect when panning a camera in game from side to side.  It will even do it on loading screens for games where there is an animated loading bar.  Doesn't seem to matter if Gsync is on or not (Gsync compatible monitor).  The only thing that seems to make it go away once it starts is to set the refresh rate to 100 (options are 144, 100, 60).  I usually run it along side my older PG279Q which is actual Gsync but even if I power it off and unplug the power cable it doesn't matter once the effect starts happening. 
 
What's really weird is just two days ago I did another DDU to rip out a 471 driver I had reinstalled to go back to the 497.29's that had run fine before this happened.  It ran fine for two days.  Then this morning it's happening again out of nowhere.  I do have the monitor running through a UPS along with the system so I don't know if it's some kind of power issue?  The UPS is an APC model with the sinewave tech (forget exactly what it's called) that make the output compatible with digital devices vs some cheaper UPS designs that output a more square wave looking AC signal.
 
Is this maybe the monitor going out?  If so how would I go about explaining this?  It's out of main warranty but I got it from Best Buy with a 4 year extended on it through Best Buy's warranty plans, but with my luck I'll haul it in to the store and it won't do it.  I've tried both a different GPU port and cable and same thing.

Sajin
So the issue occurs over both dp and hdmi? You don't have another gpu to test with?

It only occurs on the one monitor and with multiple different DP cables.  I haven't tried HDMI (didn't think it supported Gsync) and the monitor only has one of each. Strangely putting refresh rate at 100Hz though stops it.  The other monitor behaves correctly on all ports.  I did finally find a "hidden" reddit thread though talking about what seems to be this situation being an issue with these monitors and it kinda of goes away after the monitor has warmed up for a bit.  I did noticed after posting this and doing some testing for a while that all of a sudden it was behaving at 144Hz again.  Just came back in after the monitor was in standby for a few hours and it's back.  
 
So, I think at this point it's definitely the monitor, and based on what I read it sounds "normal" but I'll keep an eye on it before the extended warranty is up.  I think  few things have tied into me not really noticing it until recently.  A lot of times I'd walk by and see the blank screensaver was on but you could tell the monitor backlighting was still on so they weren't in standby.  That would contribute to me not noticing in the evening.  During the day I'm either on working from home and/or maybe daylight coming in makes it harder to notice vs night time gaming in a dark room.
 
The one thing I find weird is that setting the refresh rate to 100 instead of 144Hz out of the 60, 100,144 options that the Nvidia provides seems to stop it.  The reason I find this weird is in the game I first noticed it in I actually limit the FPS in game to 90 or 100 depending in order to leave headroom for streaming it.  So with Gsync enabled the refresh rate is already dropping to that point anyway. 
 
edit:  The only other thing I can think of but don't know how it would actually cause a problem is I have my work laptop's docking station connected to the HDMI port from the laptop's dock via a DP to HDMI cable since the monitor only has one DP port and the laptop dock is DP only (silly HP).  However the laptop is off.  I'll have to try this in my next round of testing cold vs on for a while as I only just thought about it somehow causing an issue.  The dock is powered so even with the laptop in standby I don't get a "no signal" when switching to its input.