How do you adjust xy scaling on the 540 elevation screen? It seems to randomly change during an activity and shows useless information, for example 300ft vertical on 4000ft climb. On the 1000 Explore, this could be set to auto scaling so the entire activity was fit to screen. Want this same operation on the 540. It appears the x and y scaling adjust can be toggled with hold of upper right button, but then there must be some secret combo of other buttons to actually change the scaling.