Screenshot thing sounds like a DPI issue, which Windows has been famous for. When I do it on mine the little bar comes down and darkens the whole screen for selection. The rest, fixed by using explorerpatcher.
Also, Happy Father's Day to all the mother Fer's (literally) in here!
Yah figured as much too. I have two 4K screens running at different scaling settings. Still, apps like Share-X are fine with it, so Microsoft should be able to figure it out too.