Wanneer RouteXL  de router van GraphHopper gebruikt krijg je inderdaad dat effect.
https://www.openstreetmap.org/directions?engine=graphhopper_car&route=52.26506%2C6.34173%3B52.261224%2C6.363868

..
OSRM doet het zo https://www.openstreetmap.org/directions?engine=fossgis_osrm_car&route=52.26506%2C6.34173%3B52.261224%2C6.363868#map=16/52.26374/6.35304&layers=N

en

Valhalla zo:
https://www.openstreetmap.org/directions?engine=fossgis_valhalla_car&route=52.26506%2C6.34173%3B52.261224%2C6.363868#map=15/52.26696/6.35769&layers=N

Het komt door de zandweg