Sometimes writing to iCloud does not happen. What am I missing?

I have two classes with identical parallel code writing key-value data to the cloud. One works well. The other goes through the code, but somehow does not seem to write to the cloud - at least I cannot retrieve it. I must be missing something. Here is the code:

NSUbiquitousKeyValueStore *kvStore = [NSUbiquitousKeyValueStoredefaultStore];

[kvStore setString:cloudString9 forKey:name1];

[kvStore synchronize];

NSLog(@"PersonViewController - WRITING UPDATE TO CLOUD - key = %@, value = %@", name1, cloudString9);

The log comes up and contains the expected string values. Any suggestions? Thanks.