Thanks Xavier for your time in investigating my problem. I am sure I did not have 2 sessions running, in fact on Monday I did two routes, the first one did record the achievement badge but the second one did not. I use Zwift on my Patio and the second ride immediately followed the first one. I am sure I have not had 2 devices logged into the Zwift application at one time.
I will test again in the morning although most of my routes that have not been completed are quite long and also hilly.
I would have thought that Zwift would allow updates to your stats from ZC. I can see the Achievement logo on ZC. I do need to climb a few hills if I am going to get a Tron bike, at least the elevation from the rides is being added to my total, not sure about the XP points, never check them.