I just purchased my Roku Premier and successfully set up the Home Kit for Apple Airplay - that was easily done, When I run a movie on HBOMAX from my iphone I only get audio and a title screen on the TV, the video does not stream, only the audio. I know I set it up correctly otherwise the audio wouldn't run and I can control it from my iphone 8. I have an LG Smart TV that was purchased in 2017. Can anyone help with this?