Without spending a lot of time reloading the versions of MapSource that were current at these times and studying the files, I cannot answer why the old file worked, but not the new.
I answered my own question.
The old file worked because it only had the <rtept> tags, without any <extensions> tag. The Edge realized that it has to figure out the route details on its own. It then calculated the route automatically and navigated on the road accordingly.
The new file has the <extensions> tag. Therefore, the Edge assumed that the route details are within the <extensions> tag and never bothered to calculate the route. But in the case of the new ACA files, the details within the <extensions> tags are not there. The <extensions> tags are empty. Therefore, it just connected the waypoints in straight lines. The Edge does not have the option to force a "Recalculate" and overwrite the information within the <extensions> tag (even though in this case the detailed breadcrumb information does not exist).
To prove this point, I manually removed the empty <extensions> tags from the new file AC01v007.gpx and created a test file A01010.gpx. That worked. It fixed the problem and the Edge did calculate the route and followed the road.
So I concluded that, to get the ACA routes to work better with the Edge, one needs to either remove the empty extensions or fill them up with the route details.
Again, it looks like the Edge works with what it is given. Given only the waypoints, it navigates straight lines. Given the breadcrumbs of the routepoint extensions, it uses them to navigate roads.
- Given only the waypoints: it will calculate the route on the map and navigate on roads
- Given the breadcrumbs of the route point extensions: it uses them to navigate roads. This can be very handy as it includes navigation on off road trails and bicycle paths. There is no option to recalculate and overwrite the given route points
- Given only the waypoints, with fake route point extensions that are empty: it navigates in straight lines. There is no option to recalculate and overwrite the assumed route points
I will post more on this later.