Auto-rotate during recording or while navigating helps some people guard against confusing directions. Not everyone likes having the map as North Up as they navigate.
To enable Auto-Rotate, tap the compass in the upper right of the map.
As you start moving forward, the map will orient itself to your position and heading. It does not rotate based on the orientation of your phone, it rotates based on your direction of movement.
To disable auto-rotate and return to North-Up, tap the compass again.by