I'm not sure if FreeNAS can offer any solutions since the issue is on Window's side, but I'm seeking advice. I have two FreeNAS servers bound to Active Directory and hosting SMB shares. Many of my users access these SMB shares from non-domain personal computers; connecting to FreeNAS with "domain\user". When users update their passwords in Active Directory this often triggers an SMB bruteforce attack alert from my Network Security team because Windows will continue trying the old password...
Dealing with Windows Credential Manager
Dealing with Windows Credential Manager