Contacts Framework Frequently Hangs on iOS 11


Some bug of Contacts found on iOS 11 system, and I can NOT update for fixed those bug. so, please attention that after update iOS 11.

I know that the bug maybe lost some item when number of contacts more than 500.
When user have more than 500 contacts and different group, app maybe wrong about group at save contacts.
I received those bug information:
[Contacts] Error: service connection to was interrupted
[Contacts] Error communicating with XPC Service: Error Domain=NSCocoaErrorDomain Code=4097 "connection to service named" UserInfo={NSDebugDescription=connection to service named}

I tested this bug in my account, 2900 contacts saved on my iPad, and 40 contacts can NOT saved into group Probably.
I have build 2.708 for reduce this bug, I have add code for save address book every 100 contacts, and saved group is correct.
This bug will happen at iPhone6 even saved contacts every 100, I changed to saved every 50 contacts.