I have no idea what's happened, and nothing has changed as far as I'm aware, but all of a sudden, when I checked my Whole Home Wifi App this morning, it magically connects to my network without me doing anything! And I'd deleted and reinstalled the app previously too.
There must have been a gremlin in the system somewhere , and whether BT have solved it in the background, or whether the gremlin has just vanished, I have no idea. But it's working for me now.
How strange!
No change for me unfortunately: did a fresh reinstall just now, but the app still fails to find the discs for the network that my phone is already on, and the local websites still fail to resolve.
I guess I'll keep checking every couple of days and see if it magically starts working!