Hello JGold7236,
Thank you for posting in Microsoft Community forum.
1.What do you mean about "MSE 2016"?Is it a Windows sever?
2.What is "the Connector app for MSE"?
Is "MSE 2016" also an DNS server? If so, you can set the Preferred DNS server on Windows 11 using the IP address of "MSE 2016".
Check if you can ping the domain name or the IP of the domain or the FQDN of the Domain Controller.
I hope the information above is helpful.
If you have any question or concern, please feel free to let us know.
Best Regards,
Daisy Zhou