Hi,
What's the detailed version of your Exchange 2016? You can check with the following command:
Get-ExchangeServer | Format-List Name,Edition,AdminDisplayVersion
Is the target database mounted in the same site as the source database?
Does this issue occur with other user mailbox?
Use the following command to check the database of the user mailbox, make sure the homeMDB is also set correctly:
Get-Mailbox test1 | fl Name, Database

Try to restart Microsoft Exchange Replication services on target and source Exchange server. Then use the New-moverequest cmdlet to move the mailbox. If the issue persists, try to check the move report with more details:
New-MoveRequest -Identity "<user name>" -TargetDatabase "<target mailbox database>"
Get-MoveRequest -Identity <user name>
Get-MoveRequestStatistics -Identity "<MoveRequestIdParameter>" -IncludeReport| FL
Regards,
Lydia Zhou
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