I've done a lot of trouble shooting with this (when i found the Store, Windows updates and direct downloads (i.e. the auto download / install of .net 3.5 or RSAT tools installation via command line) and discovered the Netagent 11 policy that enables WSUS was the cause.
When it's enabled it updates the registry keys in Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate with wsus info but it also adds the DoNotConnectToWindowsUpdateInternetLocations key.
I believe it's this key that's stopping the devices from manual windows updates check ins and all the other features not connecting.
Is it possible to use the kaspersky WSUS feature but without this one key being added?
From what i can see this only happens with netagent 11 (11.0.0.1131) and users who still have netagent 10 (from previous KSC server) get the wsus updates but not the DoNotConnect...... key.
You can't manually update the key because any changes are immediately reverted to the pushed settings.
Pictures added for clarification.