Something caused the minimize, maximize and close buttons to disappear for maximized windows on Ubuntu 18.04. Only some GNOME setting windows show them correctly when maximized. Minimize, maximize buttons are enabled. I can't find any settings differences between this system and another one, which shows buttons correctly. Any clues?
Files and Text Editor have the buttons when maximized:
Terminal and Nomacs don't have the buttons when maximized:
It was the GTK Title Bar being enabled, which I couldn't see because Gnome Extensions for Chrome was giving me
Application is not available errors.