Other than re-reading through the SUS Deployment Guide, you may want to double-check the clients to ensure they are not running a local firewall (or other application) that could be blocking the ports required for the Automatic Updates client to work properly. AutoUpdate being grayed-out in Control Panel, simply means that the client has been configured outside the Control Panel applet.
Dig deeper on Windows Server and Network Security
Related Q&A from Rod Trent
Have a question for an expert?
Please add a title for your question
Get answers from a TechTarget expert on whatever's puzzling you.