Expedition mode overrides the Recording Setting of Auto Start Off.
It starts recording the track data the moment that the GPS enters Expedition mode. Even when you stop the track recording, if after 2 minutes you haven't used the GPS, unless you have disabled Expedition mode in the mean time, the GPS enters Expedition mode again and the track recording starts up.
The moment that you set Expedition mode to 'Never' and have cleared the track recording, the Auto Start OFF function works again.