Domain accounts were locking when a Windows workstation starts. User is asking the Domain Administrator to unblock the account.
The Windows computer had a hidden old password from that domain account.
There are passwords that can be stored in the SYSTEM context that can't be seen in the normal Credential Manager view
Run from an elevated command line
C:\>rundll32 keymgr.dll,KRShowKeyMgr
The above command will present the stored usernames and passwords for your workstation.
Delete any stored account that causes the issue.
