Directory (phonebook) not syncing

[klmc]

I am unable to get my phone book to sync (iPhone 7S over bluetooth). It connected fine, music is streaming, the recent calls and missed calls all show up with names and all - but I cannot enter the directory (grayed out).

I have around 500 contacts in the phone - is that an issue?

Thoughts?

[klmc]

So I limited the sync to a group with just 50 contacts and that worked just fine. Not sure where the limit is but 500 seems to be over the top.

EDIT This is not correct - still trying to work it out - seems that there is plenty of space

[klmc]

Update - I managed to clear out old entires of previously linked phone. The issue appears to be the latest iOS 10.3.1 - for some reason the first time I pair the phone with the car the phone directory is populated with all my contacts and all is fine. When I come car after a while 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??

Any ideas?