tsb Good luck with a response.
In my experience this issue is also happening on other devices and platforms, it's not just a Windows 10 problem (if only).
We have a Samsung LED smart TV from 2017 which will display video from our Tivo V6 box just fine - however I've noticed the minute I switch over to a 4K channel with our cable provider, or stream a Netflix video in 4k either from the cable provider's stb or the Samsung Netflix app, I get similar 'dithering' eye strain after a few minutes. It seems OK with SD/HD content.
Maybe it's the push for HDR that is causing this? Perhaps new devices switch temporal dithering on when a 4k/HDR source is sent to it?