Route optimisation issue

During a PWC comp in Serbia (Kopaonik), me and all Pilots who used xctrack have noticed a bad optimisation route compare to LK8000 and to PWC model used to calculate the leading bonus... You can see on the joined pictures the difference between PWC and LK8000 (who give 82.9 km for the task) compare to xctrack (87.5 km task). And XCtrack take a while to change the route North to South as we already flew on south route.