iCloud duplicates contacts and groups it's frustrating
how do I prevent this from happening. Duplicate contacts, sometime triplicates, and the same with groups.
MacBook Air 13", macOS 10.14
If you have signed in with same Apple ID and password on the same network in Mac and iPhone or other apple devices the contacts on each device will get synced , if the same contacts are in devices they will be seen as duplicates ( as if you had already created contacts in Mac and the same are in iPhone ) .
To avoid it , disconnect the desired device by just signing out from Apple ID account , then delete the duplicate contacts in each device .
See this article also https://support.apple.com/en-us/HT203565