Duplicate phonenumbers in my car

[Android Central Question]

In my car i can all the contacs but some contacts have several phonenumbers. When i open these is see 2 phone numbers, exactly the same. In the phone, an LG G6, there is only one phone number and there are no double contacts. This is pretty annoying while i have to chose one of the numbers first before the car starts dialing. All of these contacts with the double number are in whatsapp as well, you can see the Google and the Whatsapp icon in the contact, i suppose that is the problem. But how can i solve this?