I have a rectangular monitor (left) and a square monitor (right).
If I try to move the mouse from the top of the left monitor to the top of the right monitor, it gets stuck. This makes it very frustrating when I'm trying to click-and-drag windows from the lefthand monitor to the right.
It's like Windows 10 decides the right hand monitor is set "lower" (see MS Paint diagram).
I never had this issue with previous versions of Windows.