Hi, I tried it with different versions of NextGen with same results. It seemed to be a inherited problem from Igo Primo which also did similar things.
I have now found the Optimize button for the route now, which has improved it a lot, however there is still a fair bit of " drive past one waypoint to reach another, then backtrack along the route to go to its next waypoint.
Instead of being a 1.....2...3.. progression it goes more, 1....3...2 and so on. Not all the time but enough to be annoying