I don't use that app but I do lose audio in certain youtube videos. I found that if I turn on night or level audio that the sound comes back although out of sync. Try that just to see if it works. While watching press the asterisk button and then change the audio.
I tried a couple of things last night but nothing seemed to work. I toggled between the night and level audio settings, adjusted the audio output formats and so on but nothing seemed to work. I deleted the app, power cycled the roku and reinstalled and same issue. I did notice that it is only the audio from the live news stream that is missing. If I run any of the news recap videos from the app they have audio.
It's definitely a Roku issue, I have another tv set up with a Firestick and the updated News 12 app works just fine.
Yes, it's an app built for Roku, but much more often than not, apps are created by the companies that want to have a presence on Roku (or any other streaming box), not Roku, itself. If someone at News 12 - or whoever they use to build apps - wrote some bad code that affects this app's audio channel, then it makes sense to let News 12 know you're experiencing the issue, no?
If nothing else, at least News 12 could then interface with Roku developer support if they think their code is good. I just don't think that posting here, alone, is going to get this fixed.