Not sure if it's desired behaviour, but my Varia Tail Light (not the radar one, just light) switches off completely every time I connect it to charger.
Thus every time I charge it I have to push and hold the button to put it back int 'Auto' mode (so it turns on automatically when Edge 520 is turned on).
It soft of defeats the point of having 'smart' portion of the light. In fact, ability to automatically turn on and off was the main selling point.
Is there any way to make Varia Rear Light keep 'Auto' mode after charging?