Go to Settings on the unit, then to Golf, down to Auto Hole Advance and make sure it is set to ON, then save the setting and exit.
For the Auto Hole function to work successfully, the unit needs to be within/inside 15 metres of the centre of the green you are currently playing and then you need to move out 19m for it to advance.
If you do not get close enough you will need to manually advance the unit by moving the centre button up to advance forward or down to go backwards/previous holes.