Why is iCloud Contact Sync such a terrible mess?
I have 3 Apple Laptops, an iPhone and an iPad.
iCloud contact syncing works with 1 Laptop (MBP 2009) and all iOS devices.
Two Laptops (Retina MBP 2013, MacBook 2015 12-inch) cannot sync contacts (rest of iCloud syncs well). I have deactivated/reactivated syncing many times, logged-out/in many times, implemented related Apple support docs and even re-installed OS X on my MBP 2013 - without success.
Sometimes, contacts changed or added via iCloud Web do sync. When I add groups, they are not synced. Suddenly, contacts are duplicated - once I even got 25 instances of a single contact - for no apparent reason.
Eventually, I had to switch of contact syncing on those two laptops, exported all contacts from the web, imported and run contacts locally.
All Laptops run the latest OS X version.
Any help much appreciated
MacBook (Retina, 12-inch, Early 2015), OS X Yosemite (10.10.4)