Just my 2¢: I’ve had the best experience with NoMachine. Yes, I know it’s proprietary. It sucks. But it works the best. I’d advise that over anything else. I’ve never had to fiddle with anything to make it work.
That said, if you want to use X2Go, you should note that the Desktop Entry for the Lubuntu session sets an environment variable when calling
startlxqt and it may be best to copy that:
env LXQT_DEFAULT_OPENBOX_CONFIG="/etc/xdg/xdg-Lubuntu/openbox/lxqt-rc.xml" /usr/bin/startlxqt
Another good idea is using full paths as the above does, as well. It may be possible that your
$PATH is not the same.
Barring that, it may be an issue with not having all the XDG variables set correctly. Look into our XDG implementation for more information.
I should add I have not used X2Go except for some really brief fiddling a long while ago so I’m more answering the question about how the session is normally started than about how to make X2Go work. Others may have additional insight.