Why isn't my GPS following the route?

[Windows Central Question]

Gps not following route.

Im having an issue with 640 xl. The gps doesn`t seem to follow my jogging route correctly. On sporttracker the route actually comes accordinly but the route looks like a barbwire, meaning that my aprox 3km route will be shown on sporttracker as 5km because it looks like ive been running on both sides of the street.

Does anyone have any solution how to fix this so that gps/sporttracker will follow the real route and not making up extra stuff?`

Thanks in advance.