Another update.
this time a happy one. I got the sunroof to calibrate and work correctly. My method.
Ensure the key is in operation II option. Push sunroof button upwards (this tilts the sunroof open). Keep finger on button. After a few seconds the sunroof will tilt close and slide open all the way. continue to Keep your finger on the button and the sunroof will slide close again. Eventually the sunroof is in the closed position...Still keep your finger on the button. While the sunroof is now closed and your finger is still pushing on the button do a slow count to 30 seconds. Release the button, remove the key from the ignition and switch the car off.
Use the remote to lock and unlock the car. Put key in ignition and operate the button as per normal. (this has just worked for me). I'm so happy that I can dance a jig.