When using the central user management sever feature of MpUserX, it is important to know that only the secure version of the protocol is supported LDAPs. The insecure version of it (LDAP) is not supported. The protocol is classified as obsolete and not supported by the main providers (AD from Microsoft).
When a connection is established to a central user management server, the certificate of the server needs to be validated to ensure that the server is a trusted partner. The solution today is to manually import the server certificate into the AR certificate store. The end-user would need to provide the certificate of their AD to the automation team and perform the update to the AR.