Riding on the A39 (UK) from near Bude towards Camelford, final destination Tintagel. Had a waypoint set in Crackington which is a diversion off the A39, rejoining it after 8 miles. The turning for Tintagel was 1.5 miles after that. Running late so I missed out the diversion to Crackington. The 450 continuously insisted that I turn round at any and every junction, despite passing the point where I would have rejoined the A39 and after taking the turn for Tintagel. This continued until I was less than half a mile from my destination. WHY? Surely your routing algorithm should have recognised that I was on the correct route onced I'd passed the point where I would have rejoined it, even if I didn't cancel the waypoint?