AAD Connect Password Sync Looks for Specific Domain Controller

Hi,

I have successfully upgraded from Azure AD Sync to AAD Connect. The sync and password sync are working fine.

I have a domain controller I wish to demote. Upon demotion password sync in AAD Connect fails with an event log entry of "Connection to preferred DC <the dc in question> failed with error 'The server is not operational."

I have unchecked the "Only use preferred domain controllers" setting in the Synchronization Service Manager. The password sync still fails and the above event log message is still logged.

If I promote the server in question back to a DC the service works fine and the event log message is not logged.

Any ideas?

Thanks

Chris

Chris Holland