Well I took my car into the dealer for them to have a look. When I went back my confidence was shattered when they said they were worried the car did not have the heated screen fitted, as they could not see the wires in the screen! I guess they need to read up the their own technology. Needless to say they didnt know what was wrong with the auto function and thought they had got it working by manually switching the screen on, tuening off the ingnition, then turning it back on. All that was happening was the 8 minute timer was remembering the activation from before the ingnition was turned on.
I am positive there is an issue with the heated screen, more than likely software related, or possibly a faulty humidity sensor.
As with many 'improvements', for example the stop start function cutting the engine before the car stops moving, and using the radar sensor to restart the engine, VW's modifications tend to be a step backward in reality. I suspect every 2017 model year Golf with a heated windscreen has the same issue as mine, and I am one of the few people that has had the screen on a previous car, and knows how it should work.
Ian