Many thanks to everyone for their checks. Apologies for not responding earlier, but I've been away from home a few days.
I have been in touch with Aquiss and it isn't an ISP issue as the support team can connect to the web site.
I have tried a second router and also a direct PPOE connection to the ONT and both have failed to connect to the web site and neither have resulted in any notable change to the traceroutes (other than the router hop on the PPOE connection).
My phone also fails to connect via the EE network.
If anybody has any ideas what I can so to try and diagnose the problem, I would be really grateful.
Edited by jaydub (Fri 17-Oct-25 21:06:16)