Q: I follow the instruction to use the group policy to register computers for adding them to WSUS. However, those added computers don’t show up in WSUS. Why?
A: After create computer group in group policy, you need to add the computers to the group policy. You also need create OU in Domain Users and Computers to match the group computer name. Please refer to this post:
How to add a computer to Group Policy so that the policy can apply to the computer