(tested in a live session of Xfce as well as a fully-updated local installation as of 2022-07-25)
Describe the bug
On Xfce, if you maximize mintUpdate's program window, do a File -> Quit, reduce your desktop resolution, then launch mintUpdate again, the resulting program window will run off the side of the screen.
To Reproduce
- boot Mint 21 beta Xfce (whether a live session or a local installation)
- open mintUpdate
- maximize mintUpdate's program window
- do a File -> Quit
- open "Display" and set your desktop resolution to a smaller value (e.g. if you were running at 1280x1024, then set it to 1024x768)
- open mintUpdate again
- observe how the program window runs off the screen
Expected behavior
mintUpdate's program window should be maximized to the now reduced desktop resolution as it does in Cinnamon, not to the previous larger desktop resolution.
Screenshots

Hardware and mintUpdate
This occurred with mintUpdate versions 5.8.6 and 5.8.7
Additional context
This issue did not occur on Cinnamon, and I did not test it on Mate.