With the iOS 7.1.2 update installed, some users have found that some of their contacts are missing. Entries disappear from the device or synced through iCloud. As a result, added to the iPhone contacts do not appear on the Mac and iPad and vice versa. The solution to solve this problem is very simple.
It is believed there is a bug with contacts associated synchronization causing the malfunction in iCloud with iOS 7.1.2. In fact, this is only a problem with the settings. If contacts are not synchronized, you must re-activate the synchronization mode.
How to restore contacts synchronization via iCloud in iOS 7.1.2:
Step 1: Open the Settings on your iPhone, iPad or iPod touch.
Step 2: Go to Mail, contacts and calendars.
Step 3: Make sure iclound is selected as your default account
Step 4: After missing contacts do not appear on other iDevices, you have to enter them manually. To find out who’s not included in iCloud, go to Contacts -> Groups.
Step 6: Uncheck All iCloud, leaving only the group “On my iPhone”.Then you will see a list of contacts missing on your other devices.