I've been having this issue for a while, so I don't think it's attributable to the Mojave release specifically...
In my Contacts app, I have All Contacts, All iCloud, and All on My Mac. Unfortunately, if I click on the All Contacts there are duplicates. Some contacts that are in All iCloud are not in sync with All on My Mac. Not sure how I ever ended up with this mess. All I really want is one list, the iCloud one, and then be able to use this within Mac iMessage. However, it appears that if the contact is not in the list for All on My Mac then all I see is a phone # in iMessages. I know my contacts are not in sync because even some of the notes differ for a contact which is iCloud vs Mac. Any ideas on how best to clean things up?
In my Contacts app, I have All Contacts, All iCloud, and All on My Mac. Unfortunately, if I click on the All Contacts there are duplicates. Some contacts that are in All iCloud are not in sync with All on My Mac. Not sure how I ever ended up with this mess. All I really want is one list, the iCloud one, and then be able to use this within Mac iMessage. However, it appears that if the contact is not in the list for All on My Mac then all I see is a phone # in iMessages. I know my contacts are not in sync because even some of the notes differ for a contact which is iCloud vs Mac. Any ideas on how best to clean things up?