Mac Contacts Not Syncing With iCloud

My Mac is set up to use Contacts in iCloud. When I open the Contacts app, all my contacts are under the iCloud heading. There is no On My Mac heading. If I disable iCloud Contacts in the iCloud Preference, all my Mac contacts disappear. If I enable Contacts again, the iCloud section appears again with all the contacts. All 392 of them even though iCloud shows only 331. The point is that adding/changing a contact on the Mac is NOT reflected in iCloud. And while adding a contact anywhere but the Mac shows up on the Mac, deleting that supposedly synced contact on the Mac does NOT delete it everywhere else.

Just did another test. If I create a note on an existing contact in iCloud via a browser that already exists on my Mac, the note does appear on the Mac and everywhere else. However, if I delete the note in iCloud, it is not deleted from my Mac, but is deleted everywhere else. Similarly, if I add a note in iCloud, wait until it appears on my Mac, and then delete it from my Mac, it is not deleted from iCloud.

I have resolved this issue with the help and suggestions of a number of people online as well as some informative articles. I believe that the problem was some sort of corruption of confusion with the contacts data inside the Addressbook folder in ~/Library/Application Support. I only have one account but it appeared as if there were a number of accounts. I also can't remember if this started with Sonoma.

What I did was to first export a Contacts Archive from my Mac. Keep in mind that in my case, my Mac has all of my contacts whereas iCloud/iPhone only had some of them even though everything was supposedly linked to iCloud. Next, after exiting Contacts, I renamed the Addressbook folder to Addressbook.old. That gave me an empty address book. I then imported the Contacts Archive into iCloud, expectingl that I would end up with lots of duplicates. I then opened Contacts on my iPhone to make sure everything synced. As it turned out, most of the duplicates were either merged or not imported since they were duplicates. iPhone very nicely shows you when there are duplicates so I was able to delete them.

Lastly I opened Contacts on my Mac and very nicely, every had synced from iCloud. Looking for duplicates on the Mac showed 6 with duplicate information but it doesn't tell you which they are. It only let's you merge however in this case it merged information only because I ended up with the same number of contacts.

I then tested by creating a contact in iCloud and watched it sync to my Mac and iPhone. Unlike before, it was quite fast syncing to the Mac. I made a change on the Mac and it synced to iCloud. I then deleted from the Mac and it deleted from iCloud. Doing the reverse also worked. So everything seems to work as expected. Case closed.

I knew I'd forget something. Before renaming Addressbook, I turned off Contacts in iCloud Settings. I turned it on once I'd loaded everything into iCloud and cleaned up in iPhone.