I have a TCL Roku TV and a Roku Ultra that is in another room. Both devices have very inconsistent audio when connected to a sound bar. The volume is sometimes dramatically different from app to app. All the apps I use, the dialogue is quiet and the background sounds are too loud. The TV speakers sound just fine.
I've tried everything that others have suggested as far as changing the audio output to Stereo, but there is no change in the audio. This happens on both Roku devices. I've tried HDMI and optical connections with no change.
I'm almost certain this is a Roku specific issue as I connected the Flexbox from Comcast and the audio works great when connected to the sound bar with no inconsistentcy.
Is there anything else to try or is it time to try another streaming device?