I'm pretty sure my issue is a bad Roku Ultra 2021. I turned on my tv, AVR, and Roku Ultra, and attempted to watch a video. The video started and played for about 5 seconds, and then the tv screen went black, and the Sony "Bravia" script displayed in bottom right hand corner, while audio continued to play. I pressed the Roku remote pause button and audio continued to play. Then I pressed the Home button, and audio continued to play. I pressed the Display button on my Sony remote, and the screen returned to the Roku menu page. I attempted to watch the Roku device a second time, and received the same results. I am currently using the provided Roku HDMI cable, and a Zeskit Cinema Plus cable rated at 22.82 gbps. I turned on my Dish box and selected the CBL button on my Denon remote. I had uninterrupted audio/video for at least 10 minutes before shutting the tv off. The Dish box works, the Sony tv works, the Denon receiver works, but now the Roku does not play video. I have tried 4 HDMI cables, rated at 18 gbps and 22.82 gbps. All updates are current.
I processed an exchange with the retailer. I should have a new Roku in hand before Christmas.
The Roku Ultra 2021 is unprepossessing!