At a guess, you need to run setup on your Chromecast again and tell it to connect to the new SSID
Have you tried logging on to your smarthub to check that your chromecast is listed as connected? If it is then note the ip address and try pinging it.
It's an inbuilt one in the Sony android tv. It all casts fine from youtube and other areas. It's just the by sport one not even showing through the app. I never had this issue with the homehub5.
I have tried turning off the smart access on the router but still nothing.
thans for your help so far