After the latest updates with the new Gnome Settings I can change the setup for external monitors.
The problem is that the system doesn't remember the settings, so after a log out (or restart or suspension, etc..) I need always to open again Gnome Settings and set the external monitor as "Single Display".
After the latest updates with the new Gnome Settings I can change the setup for external monitors.
The problem is that the system doesn't remember the settings, so after a log out (or restart or suspension, etc..) I need always to open again Gnome Settings and set the external monitor as "Single Display".