GinaroZ
I've had a look at a route going through Fort William on Maps.me. It's actually a roundabout in FW that's causing the problem. Test it out by doing a route from Oban to FW, you'll see it works fine.
See the note at: https://www.openstreetmap.org/note/2734662
P.S. you need to create an account to leave comments on notes :)