In a Microsoft Exchange Server 2019 or Exchange Server 2016 environment, in case that different Domain Controllers (DCs) for global catalog (GC) and writeable DC session are used, when you create a migration batch for mailboxes, the migration batch fails with status CompletedWithErrors without further information in the Reports.
Migration batch failure is reported due to the ManagementObjectNotFound exception thrown from the Get-MoveRequestStatistics cmdlet that's called from the MsExchangeServiceHost service running in background. After the exception is thrown, the service executes Get-MoveRequestStatistics again and the command succeeds without any exception during retry. But the migration user is still marked as CompletedWithWarnings due to earlier exception.
To fix this issue, install one of the following updates:
For Exchange Server 2019, install the Cumulative Update 7 for Exchange Server 2019 or a later cumulative update for Exchange Server 2019.
For Exchange Server 2016, install the Cumulative Update 18 for Exchange Server 2016 or a later cumulative update for Exchange Server 2016.
Learn about the terminology that Microsoft uses to describe software updates.