Primary Display Resolution: 1920x1080 60.75% -0.72%
Multi-Monitor Desktop Resolution: 3840x1080 60.70% -0.36%
maybe the "Multi-Monitor Desktop Resolution" is excluding single monitor setups, so it would make sense that there is no 1920x1080 in there
I don't see any common single monitor resolutions in that list so they're definitely excluding single monitor setups from that list, which is good