We received an update at around 2:30PM indicating that the issue on iOS had been resolved. You might have tried since then but could you please attempt to uninstall the Optus Sport application and re-install. If that doesn't work, our TV & Content team have advised to raise an in-app support case so they can investigate further. There's a handy step-by-step on how to do this here. Let us know how you go!
My Chromecast has been working with optus for months. This morning I was unable to cast Manchester derby game to Tv from my Android phone. I checked that YouTube was casting ok. What is your opinion on the problem with optus sport?