Mac contacts won't sync with iCloud

Unfortunately, the link to contact Apple support just keeps giving me the run around to the same articles that are not useful. I’ll probably have to book a support session at the Apple Store to get help, but it’s annoying that something that should be relatively simple (and that seems to be a problem for many people from what I see online) can’t be dealt with online.

The address book does not sync with iCloud at all. If I add a new contact on the MacBook, it does not get uploaded to iCloud. Conversely, if I add something to my phone, or directly on iCloud, it syncs with the phone/icloud, but not with the MacBook. Basically, it seems as if the MacBook is simply not uploading/downloading to/from the iCloud at all for contacts. It works for everything else automatically (calendar, reminders, To do list). And again, I have checked the settings, and the contact toggle button is on, etc.... everything seems fine. I only have the iCloud contacts. I am not using gmail or other accounts for contacts.

Unfortunely, this did not help…