After my 6 months experience with my Edge 830 I finally could identify and reproduce the recalculate issue which has caused frequent issue. There seem to be many discussions ongoing on this subject on this Edge 830 forum and no real solution. I disabled this feature (Profile -> Navigation > Routing > Recalculation = Off ) that is creating more confusion than aid.
Could Garmin to allow this recalculate feature to work as expected, ie to route you to the nearest point on the route. (as one could expect from a GPS device).
Hopefully, Garmin will pick this up in their software enhancement plan of this Edge 830 device.
Thanks !