I have my game running with Flexible setting for UIRoot (with 720 as min). And it works fine in Windows 7 desktop.
Problem is with Windows 8 and 10 laptops. The problem is hard to explain, but I will give it a go here..
1. When the game's resolution is set to say 1280x720 windowed in 1920x1080 desktop resolution, the game itself is fine, but the UI always looks like as if it is 1280x720 full screen resolution. Therefore the UI gets cropped out and I can't access the buttons etc. Because the UI setting is Flexible and pixel perfect, it should display fine but no...
2. When the game's resolution is set to say 1920x1080 fullscreen or windowed, the UI looks like as if it is 1280x720 ( not pixel perfect ) I can access the buttons but this clearly is not right.
My suspicion lays down to Adjust by DPI option which I have turned on. But I thought it will only affect mobile devices.. perhaps not... perhaps Screen.dpi doesn't work well for Windows 8 and 10 laptops..
In any case, I am going to try and turn that option off to see if it can help me, but just want to report this.