I'm just coming back to this, because there has been no update. Is it a problem with my installation specifically, or is it universal?
It's a real pain, because today I was flying an aircraft that required an engine start before push back. ATC then changed my anticipated push back direction. I couldn't select a direction, because the menu had disappeared. Restarting GSX didn't help either, because it wouldn't start the push back at all now, without me closing the fuel and restarting the engines all over again.
This is only a relatively recent phenomenon. It used to be the case that you could select the direction when the menu disappeared, but no longer.