We have an Element on our DMA that requires credentials (Username/Password) to access and this works fine, however the same Element that is replicated to our DMZ-DMA does not appear to save the credentials.
Are you talking about credentials that are available under DATA pages of the element or credentials under the 'Edit' of the element?
In case it is under the 'Edit', there you should find the configuration credentials to communicate to the device in case of doing that on the DataMiner system where the element is hosted; If you look at the 'Edit' for the replicated element, there you should find the credentials to connect to the DataMiner system where the element is hosted.
In case it is under the DATA pages, all parameter sets done from the DataMiner system with the replicated element will be forwarded to the DataMiner system that hosts the element. That one will then decide what needs to happen with the set (e.g. storing something local on the DMA or sending the set to the device). Once the set is performed it could result in a parameter being updated and then forwarded again to the replicated element.
Resolved the issue in the end by simply deleting the Element and the replicating it again.