You're welcome but I think the "problem" may be with the OS you are using.
There should be a visual clue - in this case, on Windows, a "bar" made of short lines - that shows there is something you can manipulate but it isn't shown on your screenshot. If the visual clue isn't there then most people will not know that there is something they can use.
Or maybe it's just not shown when a menu is open, I don't really know.