This worked for me too, THANK YOU!!
This tip has solved my Contacts syncing problems -- thank you so much "l j m"!!! I have three Macs and one iPhone. The contacts in my iPhone and one of the Macs were correct and synchronizing with iCloud correctly. One of my Macs was never getting updates, while the other Mac would get new entries, but would not reflect edits to existing entries.
I basically followed "l j m"'s instructions. Importantly, this method does not turn off syncing of Photos, which in some cases would require you to re-download your entire photo library.
1. Use a web browser to log into your iCloud account and verify that the Contacts in iCloud are the ones you want to keep.
2. On a non-syncing Mac, go to System Preferences-->iCloud and turn off (uncheck) Contacts syncing.
3. Go to ~/Library/Application Support/AddressBook. In Finder, use the menu Go-->Library (shift-command-L) to open this normally-hidden folder, then go down to AddressBook. Make a temporary folder on your desktop. Select all the files in AddressBook (cmd-A) and drag (move) them into the temporary folder. This is just in case you want to try to undo these steps.
4. In System Preferences-->iCloud, turn on (checkmark) Contacts syncing.
5. After you're convinced you don't need the old files anymore, you can delete the temporary folder on your desktop.
Now the Contacts (and Groups) on my Macs match what I had in iCloud. Preferences for the Contacts app on each Mac were unchanged. Hope this helps someone!
