Hello Hyun-woo,
If the CSV became unavailable because the encryption protector can no longer be used after the TPM/HSM firmware update, do not format, initialize, or recreate the CSV. If you still have a valid BitLocker recovery password or .BEK recovery key, the volume can normally be unlocked using that recovery material. Microsoft recommends PowerShell or manage-bde for BitLocker-protected CSVs.
First identify the affected volume and check its BitLocker state:
manage-bde -status "C:\ClusterStorage\Volume1"
If you have the 48-digit recovery password, unlock it with:
manage-bde -unlock <volume> -RecoveryPassword <48-digit-recovery-password>
If you have a .BEK recovery key instead:
manage-bde -unlock <volume> -RecoveryKey <path-to-key.bek>
Both recovery methods are supported by manage-bde.
For a CSV, also verify the cluster’s BitLocker protector configuration before returning the resource to normal operation. Windows Failover Clustering normally manages unlocking through its configured cluster protector, and Microsoft documents specific recovery-key handling for CSV resources.
I would avoid removing the existing protectors or decrypting the volume until access to the data has been restored and verified. If the recovery key successfully unlocks the underlying volume but the CSV still cannot be brought online, please provide the output of manage-bde -status, Get-BitLockerVolume, and the relevant FailoverClustering/BitLocker events.