I know you are not talking about Garmin, but the quality of the Garmin 1030 rerouting is extremely variable. I’m guessing that until you get a distance away from the route that the next way point is quicker via an alternative route, it’ll try to re route you do a circular u’turn or an actual u’turn (if there’s no handy circular u’turn). Then when you get to that distance the rerouting is perfect. So you have to go on instinct and ignore the first half dozen reroute recommendations. Its actually an improvement over my defunct 800 and 1000s so hopefully its better in newer units 
My other bug bear is despite you saying no to ‘route to the start’ it still tries to reroute you as you go to a well known start point and you might not go by a cyclepath etc; I’m quite glad my sound doesn’t work on mine or the constant beeping would get annoying