I would like to share a bug and fix I have found after update to 9.4OS and how it interacts with the Plex app.
The problem comes with leaving "force direct play" on in the Plex app. The bug triggers when I play a "volume mode" compatible stream (like AAC stereo), switch to night mode, and stop the file. If I then try to play a file with a non-"volume mode" compatible stream (like Dolby or DTS) with both "force direct play" and "night mode" still on, Roku disables all volume mode options in all apps and reports that my AVR equipment can't play any Dolby or DTS. With previous OS it would only disable "volume modes" for the currently playing Dolby/DTS stream which obviously makes sense. Now it disables these modes permanently. It makes Plex transcode all Dolby/DTS formats to AAC stereo until a factory reset or performing the below steps (provided by @StreamerUser Thanks!) :
Go into Settings/Audio/HDMI and set PCM-Stereo and Settings/Audio/Audio mode=Stereo,RESTARTyour Roku
Go back into Settings/Audio/HDMI=Auto detect and Settings/Audio/Audio mode=Auto,RESTARTagain
It's a really infuriating bug but the only solution when leaving "force direct play on" is to either not forget to turn volume modes off before playing a non-AAC stereo stream, or simplest is to leave the direct play option as "auto" not "forced" in Plex.