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.
Try removing the channel from the Roku home screen by navigating to the channel tile, pressing the * key on your remote and choosing 'Remove channel'. Then restart your device from Settings>System>System restart. Once your player starts up again, add the channel back once more.
Sam from roku customer service is a hero, while playing whatever movie/tv show on hbo max or any other channel with no sound, press the asterisk button on your remote, you with see an option menu open, go to volume mode and change it from off to leveling or night