I think it was a DNS problem and in common with the parent company Sky. I changed my PC IP settings to use Google's public DNS server and it worked. I have noticed more frequent service problems recently. I work from home and I am a night owl. I have experienced many drop-outs in the early hours recently
Posting on here means noting when it comes to broadband as support NEVER come on and post on the forum. You need to call the broadband team. See link for number.