andrew_s wrote:The flicking around is to be expected...
The 30x will give a static display if you change from "track up" to "north up", since its compass tells it where where north is. The 20x doesn't know where north is, so the north up view will flick around too ("north", and the compass page direction, are taken from your direction of travel).
"North up" just means the map is shown the standard way up. That doesn't need any kind of internal compass.