Hi @Kevdh ,
Are you able to tell A. which step of the connection process fails for the EE router when connected to the faceplate as compared to when connected with the test socket?
Presumably it must fail earlier than authentication as I would guess the credentials are correct as proved by connecting to the test socket so authentication cannot fail connected to the faceplate (if it reaches that stage).
Due to the failure of two faceplates, if you still have your old BT router, I feel that the only further information to be gained will be to see if the BT router fails differently when connected to the faceplate versus the test socket.
From the above thread, the BT router must fail authentication by the test socket and you will see this by visiting any webpage and getting an error page. They key test would be B. if the BT router behaves any differently connected to the faceplate.
There are two cases: 1. the BT router fails earlier than authentication which confirms the behaviour of the EE router; or 2. the BT router proceeds further than the EE router and fails at the authentication step (visit to any webpage gives an error page) which matches the behaviour of the BT router connected to the test socket.
I feel your input to points A. and B. above could help to progress the debugging. You may not be able to address B. if you have returned your router, so perhaps order a compatible router online for testing.
In the above, I'm assuming you have nothing else wired to the faceplate, have not tampered with the faceplate, and a visual inspect of the connections suggest the faceplate is not obviously physically defective.
