No audio at all coming from my just over 1 year old Roku Ultra. Here is my setup. I have a Samsung 75"QLED TV, New Sony 7.2 receiver. A couple of weeks ago it started with the audio sync issues and I would have to restart the Roku to get it fixed. It is annoying but it is what it is or so I thought. Tonight I go to watch Apple TV and switch over to the Roku Ultra and no audio at all. Not even the noise it makes as you move through the channels. I changed audio settings to auto and reset the roku and nothing. I then swapped the HDMI cable to a new one and still no joy. From here I moved to a different HDMI input on the Sony receiver and nothing. Since I have Roku's in every room in my house I brought in a Roku Premier+ and audio is just fine. Also just for further testing I brought in a Roku 3 and audio plays just fine. Problem seems isolated to the Roku Ultra. I've seen others with similar issues but they have audio with sync problems. Some think it is tied to the 9.2 update. I have the 4660X with software version 9.2.0 build 4806-46. Video plays just fine but absolutely no audio at all. Others have complained about poor support from Roku so instead of going to them directly I figured I would try the forums first. Any help would be greatly appreciated. Thank You.
Try doing a factory reset. My Roku Ultra stopped sending a surround sound signal even when it auto detected surround sound capability over my HDMI cable (it just sent stereo). I tried all the settings, etc. What I ended up doing a FACTORY RESET. I did that and re-signed back into all my accounts, and now surround sound works like normal. I have a feeling the last update or so borked the settings from the old OS installation... so doing a factory reset, resets all the settings to their original state, fixing the issue.