Aiui a Pure Sine wave UPS will only matter once you've switched over to the battery of the UPS, it doesn't impact quality of the regular electrical supply passing through it unless there is additional filtering occuring (not related to Pure Swine wave as such). I've several UPS' in use around the house and all are regular UPS units which have all worked flawlessly for many years. I do use a Mains Conditioner and Radio Frequency Interference Filter on my home cinema rack though, if you wanted a clean supply rather than battery backup that would probably be more appropriate.I am no expert when it comes to UPS but I have been told by the guy that pointed me in the direction of house wiring might be the issue that a UPS with PureSine is required to fix this type of issue. A surge protector wouldn't help CyberPower PureSine is recommended from him and I should just select the required total power for only my monitors leaving the PC plugged into the wall socket alone.
Ask yourself why you've never encountered the issue at the desktop or in general use though. To my knowledge, no one in this thread or those i've read has had the issue in general use. The most common factor is VRR enabled gaming either on AMD or Nvidia.