After all I think it’s somtimes really hard for an algorithm to decide what the appropriate next waypoint should be when it comes to recalculating a route. Especially if one of the “later” waypoints is nearer to your current location than any other waypoint.
Therefore if planning a roundtrip (where “start” and “end” are in fact the same location) I’d recommend to move the “end” point a little bit farer away from the location where you begin your trip than the “start” point. Otherwise Kurviger says “destination reached” immediately. I noticed this behaviour regularly after importing GPX files from another route planning system.
If Kurviger will support two types of waypoints (“must visit” and “only shaping”) in one of the future versions this issue should be finally solved.