There may be some delay after the sync is completed. This delay is an expected behaviour.
There could be propogation/replication issues from Notes to AD and AD to Notes. When you add an object in Notes or AD, CMN DirCon may not see the object right away. This is a replication issue and not CMN.
We connect through an LDAP Service and there may be some delay. Since the connection established through LDAP portal, whatever the replication/propogation time is in that portal, we have to deal with it.
If this is the case, allow some time and run the sync again.