Suspend the passive copies:
https://learn.microsoft.com/en-us/exchange/high-availability/manage-ha/suspend-resume-db-copies?view=exchserver-2019#suspend-a-mailbox-database-copy
Resume it when done:
https://learn.microsoft.com/en-us/exchange/high-availability/manage-ha/suspend-resume-db-copies?view=exchserver-2019#resume-a-mailbox-database-copy
Once resumed, give it time to copy and replay the logs. Be patient and just let it do its thing, it may take awhile.
Wait till
Get-MailboxDatabaseCopyStatus -Server <PassiveMalboxServer>
Shows all clear and near 0 on copy and replay