Thanks. I have now accessed the sites from three locations without a hitch, so your upgrade clearly addressed the problem. I noticed later that I had separated two IPs by a comma followed by a space, rather than one or the other, so if that was the problem, please accept my apologies!
P.S. I did use partial matches, but Talk Talk and Sky have a lot of possible ranges and they don’t make it easy to check what they are. I did eventually find their details via myip.ms, so that is now sorted too.
