I clicked on "Edit Menus". That took me to "Main Menu" which is also
accessible under System-Preferences. "Screen Resolution" is
available, checked and usable in Preferences. That option, when run
provides the button "Detect Displays" which detects nothing as far as
I can tell. I'm using a Samsung which is plug and play. I checked
all the available menu items - some checked, some not. Can't find
anything that looks like "Screens & Graphics".

If I click on "New Item" or "New Menu" in the Menu Editor it wants to
know commands and locations. I know neither.