We just recently changed a domain account to service account. The system ran stable for around 36hrs, before hitting error that was related to Kerberos error which was somehow a contributing factor due to SQL crash

The conversion of a domain account to a Managed Service Account (MSA) on 10th June 2026 ~4pm. When SQL Server restarted at ~10:01 PM on 11th June following a routine crash, it required Kerberos authentication to access cluster storage volume (a Cluster Shared Volume accessed via the CSV coordinator). Kerberos had been broken since 9:30 PM (Event ID 40970). SQL Server could not open mdf and returned OS Error 5. DB entered Recovery Pending. 

icacls confirmed account held Full Control on Volume throughout the incident. The OS Error 5 was returned because Kerberos authentication failed at the CSV layer — the access denial was at the authentication level, not the permissions level. 

But what striking is that this routine SQL crash is occuring now and Cluster is restarting the SQL but still the there's no issue with kerberos failure and system running as usual. I couldn't exactly pinpoint what caused the kerberos breakdown and all the breakdown. However the service account is reverted back to domain account. (got to figure out something before the password expire after 30 days or we back to square one).

Any help will be greatly helpful. Thanks in advance.

Command: 
Get-WinEvent -LogName System |   Where-Object {     $_.TimeCreated -gt '2026-06-11 21:00:00' -and     $_.TimeCreated -lt '2026-06-11 22:00:00' -and     $_.Id -in @(40960, 40961, 40970, 1030)   } |   Select TimeCreated, Id, ProviderName, Message | Format-List

Output: 
TimeCreated  : 6/11/2026 9:30:54 PM 
Id           : 40970 
ProviderName : LsaSrv 
Message      : The Security System has detected a downgrade attempt when                contacting the 3-part SPN ldap/TPW-DCADC01.TPWODL.NET/TPWODL.NET@TPWODL.NET with error code 'The attempted logon is invalid.'                (0xc000006d). Authentication was denied.   

TimeCreated  : 6/11/2026 9:30:54 PM 
Id           : 40970 
ProviderName : LsaSrv 
Message      : The Security System has detected a downgrade attempt when                contacting the 3-part LDAP/TPW-DCADC01.TPWODL.NET/  TPWODL.NET@TPWODL.NET (0xc000006d). Authentication was denied.   

TimeCreated  : 6/11/2026 9:30:54 PM 
Id           : 1030 
ProviderName : Microsoft-Windows-GroupPolicy 
Message      : The processing of Group Policy failed. Windows attempted to                retrieve new Group Policy settings. Computers joined to the                domain must have proper name resolution and network                connectivity to a domain controller.