well.......your suggestion of manually setting the DNS to 8.8.8.8 worked!!!! Both Lan and WiFi originally had '192.168.1.254' on 1 line and underneath that was a line starting with 'fe80::1a82.... ' (I've omitted the rest in case I shouldn't be displaying it!). So is that original value of; '192.168.1.254' wrong? Or if correct does it indicate that the hub isn't doing something it should? Either way - it's working again (as a check I temporarily restored those original values and it returned to not opening any pages).
Thanks so much for the help!
p.s. - I did try to mark your post as the solution but just get an; 'Request Entity Too Large' error page?
It just means you are bypassing the hub and BT's DNS servers by going direct to the Google servers.
By using 192.168.1.254 (which is the address of the hub) you are getting your DNS information via the hub and BT's servers.
The other addresses will be IPv6 addresses. You can use Google servers for IPv6 as well. They are 2001:4860:4860::8888
2001:4860:4860::8844