you can use 2 filters which will enable all your extension sockets while allowing you to maintain your test socket connection
you need to connect to test socket to improve your connection until you can find the problem with your internal wiring.
you should also check your sockets and see if the bellwire is connected to terminal 3 and if so rmove it from all sockets
if you connect to test socket then none of the extensions work? the extensions should be connected to the back of the detached bottom half of the master and therefore won't work when you use test socket
john46 easier to see than mine - shrunk mine to much lol