I
had the same issue in singleplayer. I thought. But then by accident I did this:
hover the mouse over the map, press spacebar and
keep it pressed (this is the important bit), wiggle a bit with the mouse around the area on the map and voilà! It worked! But your steering wheel may act out a bit, so keep your fingers away from the wheel. And your car might not face the correct direction. But it works now for me and I can finally learn segments of very long tracks
EDIT: and no, don't use the wheel for that. It may jolt so much that you hurt your hands. I'm driving with VR and have a cheap little bluetooth keyboard with trackpad. That does the trick for me.