When we create a new window at run time, we request that it be placed
at a specific size and location, but afterward we ask the OS for
details about where it was actually made and then update the window's
size and position with the correct information. Unfortunately when we
open a window when loading a blend file we do most of this, but only
update the size from the OS, not the position. There are times a window
will need to be placed somewhere different than we request and so the
window posx and posy will be incorrect until we move or resize it. This
is more likely to happen on Macs, but is possible on any platform.
Pull Request: https://projects.blender.org/blender/blender/pulls/127819
23d0034a1b