On my 2013 JX, there is a limit on how many contacts can be synced.
afraid I don't remember the max number.
If I am going on a long trip, I just "select" a couple important groups in my contact groups and sync those.
I remember reading that if you have multiple phone numbers within a contact, it will count as multiple contacts in your sync.
Hope this helps.
I find it easier just to use siri to call the person in my contacts. It's a lot more cumbersome to do it through the Infiniti system IMO. This way I never have to take my eyes off the road or move my hands on the wheel to press any buttons.