When two monitors are available, both with different scale factors, then
the drag-image may 'detach' from the mouse while the image's top-left
coordinate was on one display, and the mouse cursor was on the other
display.
This happened because, on Windows, the mouse cursor moves continuously
in physical (not logical!) space. In other words, the mouse may not move
continuously in logical space, and the discontinuity becomes visible
when components are positioned relative to the mouse in logical space.
In order to display consistently, the top-left position of the image
must be set relative to the physical position of the mouse.