Mac will not sync some of my Contacts to iCloud
I've tried everything I have found in other syncing problems posts. Toggling Contacts on and off, Shutting down & restarting, etc.
My Mac's Contacts contents total 557 cards.
My iCloud Contacts show 369 contacts.
When I sync to iPhone or iPad Mini, I get 369 contacts. That is to say, I cannot sync all the Contacts I see on my Mac.
There may be some small differences (20 or so) if I add or exclude a small Group.
The 188 missing contacts appear to be randomly spaced in my Mac Contacts list, and either singly or in blocks, and both recent and old contacts are affected.
My Mac is a 2011 21.5", and I can't download Mojave, but this problem started long ago.
Now running Mac OS 10.13.6 High Sierra.
Calendar seems to be unaffected.
I would welcome some help! Thank you.
Robin Oram
iMac 21.5", 10.13