Help & troubleshooting for channels on your Roku device, including adding/removing channels, logging in to, authenticating, or activating a channel, channel-specific playback issues, assistance contacting channel publishers to report issues, and adjusting channel-specific settings.
I am watching Frankenstein Chronicles, for what it's worth. I still have my Amazon Fire TV 4K, and when I swap my HDMI cable to my Fire TV, the audio is fine. Unplug it and plug in the Roku, and the voices are distorted. As such, I do not think the problem is the HDMI cable.
When I choose standard audio, there is no distortion. It is only happening when I select 5.1.