I called the ISP, again, and was instructed to plug a laptop in by ethernet cable and to log into the router settings and uncheck a box for synchronising 5GHz with 2.4GHz. Then rename the 5GHz so we can identify it and then we were to log all of our devices onto the 5GHz channels. That didn't work as none of our devices would log into 5GHz. We were then advised to give it 3 hours and try to log in again. No joy. I don't know what this change is supposed to do but 24 hours later we still can't connect on the 5GHz band but connections on 2.4GHz seem to be staying up for longer than before.
So, what was the change supposed to do?
Why would it take 3 hours or longer to happen?
Non the wiser but feeling that a bit of progress has been made......
Rans6..............