I have done that and can use the main phone. The extension phones aren't working though, as per my orignal post.
Not totally sure if this is appropriate but it might be.
Before moving to Digital Voice (DV) did you have the Dect base station plugged into an extension of the copper BT line? If so does that extension and wiring still exist? The reason for asking is that if the extension socket(s) still exist you can buy a cable that allows you to plug into the BT Smart hub at one end and the master socket (or an extension socket) at the other end, then you can plug the Dect base station into an extension socket. If the Dect system previously worked giving a decent connect everywhere needed plugged into an extension socket this approach might get you back to that position. You could also plug in a normal BT landline phone into any extension at the same time.
I’ve tried all that many times, and still a couple of them don’t work
if you have the DV adapter sent by BT did you try connecting adapter to a power socket away from hub and seeing if you can pair the adapter to the hub and if so then connect your BT3510 base to the adapter and see if that works. if it works then check the 3510 extensions to see if they connect to the 3510 base
I didn’t get an adaptor
my reply was for the thread originator @Lila
Will there be any difference though whether I put the main base in the adaptor and try to link the other 2 phones to them? The main base is already working in the hub. I suspect the BT wifi signal isn’t great anyway so not sure adding an extra layer will help any.
You are not using WiFi, you are using your existing cordless phone's DECT signal.
I'm struggling to understand the problem, the only difference to what you had before is where your cordless phone base station plugs in.
As I and @licquorice posted your bot connecting phone with WiFi as they connect using DECT.
I am hoping if you move your existing BT3510 base to a more central location and connecting adapter to mains, pairing to SH2 and then plugging the BT3510 base into adapter then your extension phones will work.
This is not a problem caused by digital voice
@imjolly I don't understand how this is not caused by digital voice as the only variable that has changed in the set up is plugging the main phone into the BT hub, due to BT stopping my landline service. The main phone's physical position hasn't changed. The extension phone positions haven't changed. How will moving the phone to a central location - although it's actually in the living room so pretty central already - help any?