I’ve had the same issue for like 2 months. Brand new roku box and connecting DIRECTLY to my Dolby Atmos Samsung soundbar through HDMI.
this problem happens to me when I fast forward or rewind video - the sound will no longer play on any video in any app. However, i can still sometimes hear the menu sounds on the home screen. If I go into sound settings on the roku and change to stereo, this fixes the problem, but then i only get stereo output. If I reboot the roku, it all works again until I seek within a video. I’ve completely reset the roku as well and all of this still happens.
Mine just did the same thing. I didn’t even switch apps. I was watching a show on Hulu next episode started. I click skip intro and suddenly the screen freezes. I exit to main menu go back in sound is gone. I go to Netflix same problem. I restart my tv because I didn’t realize at first I could hear the sound when scrolling through Roku menu. Thanks to the person saying restarting fixes the problem because I recently bought a Roku tv for my living room and I would be mad if this happened to my new tv and I didn’t know how to fix