Kubuntu 18.04, as a pleasant surprise, had the super key as shortcut for the application menu instead of the more traditional Alt+F1.
I had to remove the panel and add a new one, and the super key didn't open the application menu any more. Now when I attempt to add a shortcut for the application menu, it doesn't allow just the super key by itself as the shortcut like in the old days.
How can I get the super key shortcut back?
Just figured out. Setting the shortcut to Alt+F1 for the application menu automatically enables the super key as a shortcut for it.