The native resolution of my laptop's 15.6" display is 3840 x 2160. Unfortunately, I found that the graphics on many applications didn't scale appropriately for this resolution, and were pixelated/blurry despite checking or unchecking the option in the Compatibility pane for "Display display scaling on high DPI settings".
I'm really troubled by some issues that started showing up shortly after doing the whole "new hardware support" upgrading yesterday. Among other things, Ubuntu now seems to take longer time to boot, but the most glaring issue is that the Display settings are all messed up!
I'm on a laptop, and the display settings show that apparently I should have a second laptop monitor, which I don't.