I recently installed Ubuntu 17.10. Sometimes, when I return to the PC and the screen is locked and I unlock it, all previously opened windows are gone. I truly don't understand the rational for this behavior.
I'd like to know how I can configure the system so that the windows are still present when I unlock the screen again.
Edit: it appears that I am running Gnome as window manager.
$ printf 'Desktop: %s\nSession: %s\n' "$XDG_CURRENT_DESKTOP" "$GDMSESSION"
Desktop: ubuntu:GNOME
Session: ubuntu