While testing the cross-forest migration of a mailbox, I ran into an error.
Microsoft.Exchange.MailboxReplicationService encoutered an exception. Error: MapiExceptionNetworkError: Unable to make connection to the server. (hr=0x80004005, ec=24r23)
This seems to happen when the server is not able to reach the server by using its NetBIOS name. After resolving the DNS issues I was able to run the New-MoveRequest command without any errors.