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 changed the resolution of the display to 1920 x 1080, and from what I understand, if the scaling is correctly applied, the display output should be equivalent to 1080p resolution on a 1080p display of the same screen size, as 4 pixels on my display would correspond to a single pixel on that display. However, items on my screen appear to be very small, as you can see here:
I'm not sure if this is the intended size of icons, taskbar and windows, but when I set the scaling to 125% (medium), some applications begin to have pixelated/blurry images again:
Is the 100% scaling the default scaling for 1080p (4 pixels to 1 pixel), and why does the blurriness/pixelation sometimes occur when I increase the scaling? Is there any way of fixing it? This is an example of the blurring of some programs at 125% scaling, which is non-apparent at 100%: