AVAST SOA suddenly not detecting clients.

Our AVAST SOA is running on windows 10 standalone laptop. It was working in the past 3 months but now all clients status are disconnected.

on the laptop firewall, defender, essentials is off and no settings were changed this past 3 months except the windows update. And all of our client are all running windows 7 pro, all default settings except group policy but we dont use active directory.

any help here?