there is a problem if you use a filter in the test socket and cannot get your internet connection is your master socket like this.
if so you need to remove the middle section shown by yellow arrow then you will be able to connect to the test socket shown by black arrow
Thanks yes I have done that and with a filter I get no connection. My master socket looks like this...
I have removed the front plate and connected with a new filter but no connection.
you need to remove the bottom half then the middle section just pulls off and then you can see the test socket connect to that with a filter if still no internet connection then there is a wiring problem in your home
it means there is a problem with your wiring and is it possible that although that is a filtered master socket that it is being fed from another socket in your home. is there another socket where the openreach cable enters from outside
does a phone work if you connect to the same filter