I run Roon on my HTPC which is connected to my 4K projector at 4096x2160.
I keep seeing a white box in top left corner as I move my mouse around. This is very annoying. I takes up about a third of the horizontal and about a third of the vertical screen. It only appears for half a second and then goes away. It appears in full screen mode and if minimized to a smaller size. If I move the minimized size window to the left the white box stays in the top left corner and does not move with the Roon screen. The redrawn region in Roon gets smaller and disappears as I move the Roon display to the right since the redraw appears to be a fixed size.
I am running the latest version of Roon on Windows 10 with a Nividia GTX 980 video card.
From my experience 4K screens are not properly supported in windows yet not Roon in particular. I get many anomalies on 4K screens with different 2 graphics cards and 2 different monitors. If it goes into screen saver it collapses the screen to a quarter the size moves all the icons. Annoying but it seems it is standard from all the other people saying the same thing on the internet.
I run my 4k screen with a 1080 desktop. Works like a champ on my TV.
What kind of scaling are people using on a 4K monitor. Mine is 43"
I have scaling set at 200% (Windows 10), but it doesn’t look great.
I have a laptop with a 4k screen, which has apparently been set to 250% since I bought it. I’m pretty happy with how Roon looks with that setting personally, but your mileage may vary.