I remember coming upon this when trying to use PCoIP for remote access to workstations after the win7 to win 10 transition. It's a setting somewhere in Windows10 (maybe with specific video cards?) that uses dithering to improve image quality when you have a monitor that doesn't support HDR.

This absolutely wrecked the bandwidth as the whole screen was trying to refresh at 60Hz in a way that the PCoIP algorithm wasn't prepared for.

https://en.m.wikipedia.org/wiki/Teradici