Tracks (marked with "Always Display") are shown randomly with straight lines. See screenshots below.
However, after disabling/enabling "Always Display", it will be shown correctly, nicely following the road, without straight lines.
So this is clearly a software issue, not a problem in the track itself. (it is also correctly shown in Basecamp and Mapsource and Strava)
This bug makes it impossible to navigate from one track to another, because it is very inaccurate. (when e.g. 2 tracks are marked as "Always Display")
Please solve this asap.