If you are using LDAP integration with AEM then after applying Oak 1.4.10 or 1.4.11 LDAP user and group synchronization no longer works. The user can log in to AEM, but when they do all the synchronized properties are removed from the profile.
This is a regression bug of OAK-4344.
If you don't know which LDAP properties you are using then you can refer to your Default Sync Handler configuration. Search for DefaultSyncHandler in the http://host:port/system/console/configMgr UI. The sync'ed attributes would be listed after the = in each entry of User property mapping and Group property mapping. Only the attributes that are not wrapped with quotation marks (") are the LDAP attributes.