yes a UPS with a built in power conditioner could do the job.
usually what your referring to 60Hz hum in the power line. and visually you will see this in a monitor as the bar move from the bottom of the screen to the top.
other things that can cause this effect are florescent lighting in the same room along with monitor refresh rates, try changing the refresh rate of the monitor in settings.
I tried plugging my monitor into my UPS and unfortunately there was no improvement in regards to the distortion. However, reading the specs on my UPS is seems to have no power conditioning ability beyond basic voltage regulation - so I wouldn't expect to see an improvement. However, I believe your idea about the refresh rate being the culprit is spot on.
I've done some refresh rate testing and have some interesting results:
60Hz - No ripple distortion apparent
100Hz - No ripple distortion apparent
120Hz - Ripple distortion visible
140Hz - Ripple distortion visible
With these results I think the idea of power line hum is a bit less likely. Additionally, I never ran into this issue with my prior 21:9 monitor. If this problem were being caused by dirty energy wouldn't I have observed the same effect with my old monitor? Also, I've only ever observed this distortion when the monitor is displaying moving imagery. If it were a power issue wouldn't the distortion be present during static imagery as well? Anyway, any ideas on why this only seems to be occurring at higher refresh rates? Thanks so much for your assistance, you've been a huge help!