Hi there, I’m in a new build and I have FTTP, my white openreach box has a cable coming from Tel1, which then goes into a phone socket, which in turn has a cable coming out of it which then feeds into a grey open reach box, which in turn has a cable coming out of that and back into the white open reach box into the optical port (this is all in a cupboard which is under the stairs). I then have one phone socket at the back of my TV, built into the media plate. My DECT master handset is plugged into a DV adaptor which is plugged into a socket on the media plate. Does that help? It’s plugged in as per the instructions I got with the DV adaptor and has worked fine for the last 6 months.
As per these instructions…
https://www.bt.com/content/dam/bt/help/user-guides/Digital-Voice-Adapter-userguide.pdf
The tel1 port doesn't have any function and should be disconnected. The DVA simply needs to be plugged into a mains socket and the DECT base station plugged into the DVA
I didn’t set that up, BT engineer did when my FTTP was installed. So I’ve not touched any cables. And the DV adaptor is plugged into a socket and the DECT master plugged into that as you say.
Ok, you could remove the cable from tel1, but as long as you are not connecting anything to any phone sockets there is no problem with how you have things connected. Your previous posts seem to suggest you were connecting to a phone socket