Transfer or seize FSMO roles – Windows Server | Microsoft Learn

Note. We recommend that you only seize all roles when the previous role holder is not returning to the domain. If FSMO roles have to be seized in forest recovery scenarios, see step 5 in Perform initial recovery under the Restore the first writeable domain controller in each domain section.; After a role transfer or seizure, the new role holder does not act immediately.

https://learn.microsoft.com/en-us/troubleshoot/windows-server/identity/transfer-or-seize-fsmo-roles-in-ad-ds