Why wont my device work with voice call in vehicle?

[AC Question]

When I connect my S6 to bluetooth and it pairs successful in my truck, I can give a command to call and it will repeat back the command but the ring tone and pick up does not come through the truck speakers. I have tried other peoples phones and it works fine so why is it that my phone does not work with the system it did at one point but all of the sudden quit working