The issue may be caused by the latest iOS 10.3.1?

I did a complete Factory Reset from the car which claims to delete all content.

When I then pair the phone (iPhone 7+) with the car the phone directory is populated with all my contacts (420) and all is fine.

When I come back to car and start the engine the Directory is no longer available (can't click on the icon even), however, the recent and missed calls are showing up fine with the names of the entries - just not the directory?? I understand it could take some time - but even after 30 min drive it is not working.

Any ideas?