The 'working at long distance and pointing in random directions when close to the Waypoint' is usually associated with a lack of GPS accuracy, if you compare a GPS with say 20 metre accuracy with a GPS with 200 metre accuracy, they will both point roughly to a Waypoint that is say 1000 metres away, but the 200 metre GPS will struggle with direction when it gets to say 200 metres because it own position is moving about so Much
I wouldn't say this is normal for a GPSMAP 67, try standing still I an open area and watch a zoomed in display of the map screen, if you see large random movements of the Track I would say GPS accuracy is to blame
