I suspect Sky have changed something - they owe me a callback so I’ll ask
I still think it's more likely that you were blocked at the website end.i.e. their provider\host blocked a number of IP addresses including some from Sky.
If Sky were blocking you then you normally get an error page etc.
Let us know if Sky say anything other than guessing data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7
Received a call back from Sky today - they insist they haven’t made any changes on their network , but I have been able to access the site since Saturday
i can can only put it down to a blip , I may never know what really happened !