I have a solution (for me)
Sky was falling to open on a desktop and laptop.
Desktop is a new build and new install of windows 11 and Sky Go. Connected via Ethernet and Wifi
Laptop is old with Sky Go already insatalled.
Neither would open
ISP is Three (Enough said - it's not great)
So I though may be an ISP issue.
Sky Go does open on phone when connected to Wifi (Maybe phone seen differently and ISP allows it)
Turned off phone Wifi and put data on, connected desktop to Phone via hotspot (TalkMobile- Vodafone network)
Retried openeing closing Sky with hotspot turned on/off as various others suggest and with patience it worked.
Sky opened on desktop and part of inital set told me some of the firewall settings needed adjusting and it made the changes for me.
Using the same hotspot method I also managed to get laptop working.
Turned off Phone hotspot and back on Main house Wifi and it opens still.
I tried for weeks using the wifi on/off method without success, it was changing to mobile hotspot which got me over the issue, matbe it will work for others.