Trying to perform an initial Exchange Full Sync and getting an error on importing the Exchange servers.
The error message:
"Start processing objects / relation of type "MSEXCHEXCHANGESERVER" using following settings: Database set : DELETE, Intersection set: UPDATEDB, Namespace set: IMPORT - USN optimization False.  Object list from the target system has 2 elements.  Inserting object o=Domain\/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)\/cn=Configuration\/cn=Servers\/cn=EXSERVER, type Server into database failed.  The names for server, hardware and the properties NT account, AD account, domain and AD Container have to match."
If a computer already exists in the Hardware table, then it will appear under Server | Server hardware without server in the ADS settings.
The same error can be reproduced if you try to create a new Server object while the Hardware entry exists:
In order to create the required server(s) use the "Server services" option under "Tasks" for the Server object under Server hardware without server:
Then select a server by clicking the green plus button:
This will assign the relevant hardware and create the entry correctly in the Server table. Be sure to select the "Language" then save your changes. If the new server is an Exchange server, be sure to select "Exchange server":
Following the addition of the required Exchange server(s) the sync should complete successfully.