Hello,
having exactly the same problem as ray_in_frisco. Tried many times to turn off and on again the iCloud account in system preferences as well as the checkbox in the contacts settings for the iCloud account without no luck. This is very strange, because some contacts are loaded into contacts.app are some aren't.
On my iPhone and on icloud.com all contacts worked properly. But after trying to fix the issue on my iMac, they are now messed up somehow as well. There are many duplicates and some without profile pictures. Currently, after deleting "~/Library/Application Support/AddressBook" a few times and letting it being recreated by starting contacts.app, there are no more contacts shown on my Mac but the default "Apple" and my own vcard.
Checking https://www.apple.com/support/systemstatus/ everything on the servers seems to work fine. I also tried another tip, downloading all cards from iCloud.com and importing them into contacts.app. Then they are shown there but not all of them and when looking at the iCloud.com contacts interface, many contacts are not only duplicates now but existing 3-5 times. What's the problem here?
The last few days I had the Macs hard drive being replaced due to failure and now there is this known problem with the fan speeding up because it's not a hard drive with Apple firmware on it. Might this "different" (which by the way it really isn't) hard drive be the cause for this sync problem? I hope not 😟
So what can I do now to get my contacts back?
Appreciate any help,
Kind Regards Timo