Oh dear! I tried your suggestion but I seem to have lost everything now, including my original hotspots which aren't detected by my devices at all. The new hotspots do show up on my devices but as previously when I try to connect, the process gets stuck on the 'Obtaining IP' bit. Help!
See "How to add more Powerline extenders to your existing network" toward the end of the user manual
You can only have one extender network i.e. only one of the extenders can be cabled to the router
I would completely factory reset everything again including the extender connected to the hub and then just try connecting one hotspot on its own before attempting another. Then add one at a time making sure each one works before moving on to the next. Don't use the clone feature to give them all the same ID then you will know which is which.
Have done the factory reset to both extender and all the hotspots individually as suggested (twice) and although my devices now detect the hotspots I'm still getting the IP configuration failure message. Any further thoughts?
Is that with both wifi and Ethernet or just wifi?
I guess the next thing to try is a factory reset of the hub by pressing the recessed button with a pin for about 20 seconds until the lights flash.
Find the WiFi MAC address on the back of the BT WiFi extender(s).
Login in to your router (192.268.1.254) and find your IP4 settings page.
Check your DCHP range is not too narrow.
Find IP4 settings and assign a fixed IP (within your DCHP range) using the MAC address of each extender and give them all an individual IP address.
This should allocate a fixed IP address to your extender(s). It will also make it easy for you to login to the admin page of the extender using the IP you set.
If you want you can now login to each extender individually using the assigned IP addresses and give them all the same SSID/WPA2 Key so you don’t have multiple routers.
There are a number of flaws in your post.
1. For some reason best known to BT, the hotspots don't appear in the hub's network map so yo will be unable to identify their address.
2. Giving them the same SSID is a bad idea as (a) you won't know which hotspot you are connecting to and (b) won't be able to force a switch to a better signal if required.
3. It won't help with the main problem at hand with lack of connectivity.
Fzero's suggestion is a bit above my pay grade! Anyway, I've done a factory reset on the router but still getting the IP configuration failure message; also tried further factory resets on the extender and hotspots afterwards but still no luck! Have we now hit the buffers?