I have had an issue with the 'alternative' Green route on several occasions now when riding a track. The last time this happened was after a short pause to fill up the tank. When the device came back from sleep mode there was suddenly 1h45 added to my arrival time. A bit later a faster green 'alternative' was proposed which pretty much deducted that added time again. I followed the 'alternative' and when i came home i double-checked and the 'alternative' route turned out to be my original track.
First of all i don't understand why the device would suggest alternatives when i am riding a track. The whole purpose of a track is to ride exactly as planned. And secondly i understand even less why my track is suddenly changed by the device in the middle of my ride.