Case
I added a contact and an event in the iPad version and synchronized. Then I opened the iPhone version and synchronized, but the new data is not shown in the iPhone version.
Goal
Data between multiple mobile applications synchronizes properly
Solution
As a temporary solution, I would recommend you to clear cache on the target device mobile application. This will cause full synchronization, which means downloading of all records, alternatively to partial synchronization, which download only changed ones.
Necessary conditions
The user should have the rights to use the mobile application.