Indeed, a restart of Windows is always a good idea in these circumstances. But the problem persists.
Each successive display of the editor window starts by gradually moving up the display until the title bar is pretty much hidden and may then move down to the right with the bottom and right sides of the window beyond the edge of the display. I drag it back to a more central position but this is never remembered. Also the size of the window reverts to some default size even after I've reduced the size.
Snipping Tool Version: 11.2403.8.0
Windows 11: 23H2 Build: 22632.3257.
It seems to have a mind of its own.