I bought a Roku 4660x (9.2) and connected it to my Onkyo HT-R391 receiver which worked fine with the Roku Stick 3500x. It flickers from the Roku menu, to a black screen, and a static screen constantly and so fast it's hard to even read the menus.
The TV's HDMI "display box" goes from 1080p at 60hz to blank, and back.
I tried it with a direct connection to an older Toshiba 32AV502U television and that works fine.
Then I connected it to my Sceptre X405BV, a much newer television, and it has the same flickering problem.
I changed the auto display settings to DISABLED and it still does it. I tried different TV HDMI ports and different cables and it still does it. I did a factory reset. I disconnected power from everything then tried and it still does it.
Why is it working fine with an old TV and not with the new one? The Roku 4660x says it's set to 1080p and HDCP 1.4. The TV agrees.