I spent a few hours on this one cause I couldn't figure out why you were having problems.  That section of road was correctly marked as bi-directional 2 years ago and the other routers were not having problems.

I believe the issue is that with the motorway link tag on sections of road where it's not generally used.  It's generally only used on one way links so it's possible it was causing the navigation issues.

I have changed the classification of the roads and hopefully that resolves your issue.

Please re-open if it you still have the problem after your vehicle's map updates.