@Jack-van-Tilburg
I guessed that might be the way to do it and it's what i need but it's read only when i import a GPX track using import route:
You can see the GPX track on the picture above.
The only option i can find is edit route track which converts the track into a route and creates various waypoints which do not follow the track accurately as it's off road.
Unfortunately the track is not displayed so i can't update the waypoints / route to match the track:
As can see in the picture there is no track and the blue Track from the south is diverted along another road in the north incorrectly.
I need to see the original track from GPX so i can correct the route and make it match correctly. Your message indicates that's possible but i still cannot work out how to do it.
Thanks.