Hello John,
Today I was trying navigation instruction, and the DMD2 suggest me a road, i take a different one, and DMD try to recalculate, but after few second stop the navigation and it remain only the map.
I will try again in order to understand if was an isolated case or if it happened in same specific case.

If you have a GPX loaded you have 2 options: Navigate to START or to END, are you working also in the option to NAVIGATE following the GPX without any calculation?
An in case you go out of the track recalculation must bring you back to the track.

I`m organizing a trip up to Nordkap and I have created GPX for all the different Days… would be great to have the turn-by-turn indication in order to follow the track we have decide the take.
Just follow the line on the MAP, if you are on normal road following a long trip (300-500 Km) could be difficult if you have lots of direction change.