I noticed a bug on my Roku Ultra tonight. Every app I opened and tried to play content on retuned a scratchy Audio sound. I checked the audio settings and it was set to Auto-Detect. I switched the audio to PCM-Stereo and that has solved the problem for now, but seeing as I always have my Roku set to the Auto-Detect setting since it is only plugged into an HDMI switch that is plugged into my television.
I don't know if a firmware update is in the works that has something to do with the bug that I think has affected the Auto-Detect setting. Just thought I would helpful and pass along the info.