Have 3 of the Roku Premier 4k devices, 2 of them are having the same issue. Sound isn't working when we go to an application to play a show, but when you hit buttons you can hear the pointer/selector making noise when it moves or the sound it makes when you hit the home button. Confused by it and not real sure what to do, anyone have any suggestions? We factory reset the one and that didn't work.
Ended up factory resetting them a few more times and finally they started working again, not entirely sure what the issue was as we never figured it out. Factory reset and unplug it and let it sit for about 20 minutes, hopefully it does the trick for ya!