At least daily we are having to reset our Roku because of audio and playback issues. Suddenly the picture will be zoomed in so that only part of the picture is visible or there will be no audio, regardless of channel or volume.
The only way to fix these issues is to unplug the Roku device from the TV, wait a few seconds, and plug it back in. We may be in the middle of a show or movie when these issues occur and will have to go through this process and find the program to resume watching.
I wish I had an answer or help for you but I don't. I am having the same issue as well. I even switched my Roku to a different TV but continues to happen. Currently, it will not reset the volume. I can view the program but can't hear it. I have looked all over the "help/support" and can't find a resolution to this issue. Resetting is not working for me. I hope someone has an answer since I am unable to find even an email to ask Roku directly.
During any program, my screen keeps flashing -- either a white flash or a black frame -- every ten seconds or so. Making it impossible to watch anything. No phone support and no meaningful online support. I'm sorry I ever paid a penny for this terrible little device that's proven so unreliable during the time I've owned it. It's worthless junk!