Some Roku Apps stream audio using Dobly Digital 5.1 (not plus) most stream only PCM stereo?
My audio issue is that most Movie streaming apps only will stream with PCM stereo audio (e.g. Vudu, Netflix, Movies Anywhere, Pluto TV apps) despite explicitly supporting Dolby Digital+ 5.1 source audio.
While the Youtube, Youtube TV and the Roku Channel apps do stream audio properly using Dolby Digital 5.1 (not plus).
As an example, I can play the same Movies Anywhere movie via YouTube and get proper 5.1 but only PCM stereo via the Vudu Roku app. Both apps link to the same Movies Anywhere account.
My Roku 3930X is connected via HDMI to an Amazon Basics brand HDMI optical audio splitter. An optical audio cable connects the splitter to my Sony STR-DH500 receiver that does support DTS and Dolby Digital (not plus) decoding via optical audio but does not support Dolby Digital decoding via a direct HDMI connection at all despite having HDMI input ports. The Splitter is also connected via HDMI to the receiver which is passed through to my 1080p video projector. Video is working properly.
My receiver's front display shows me the audio stream type of PCM 48 or Dolby Digital 3/2.1 (5.1).
Roku Volume Leveling Mode is set to off.
Roku UI sounds are off.
Roku Audio Mode is set to Auto (DD, DTS)
Roku Streaming Audio Format is set to Auto (I've also tried the Dolby option)
Roku Digital Output Format is set to Auto (I've also tried the Custom setting option of Dolby Digital (not plus)).
None of these fixed my PCM input issue. I assume my issue is related to the streaming apps not having a Dolby Digital audio fall back option opposed to the more current Dolby Digital Plus 5.1 or Atmos audio formats. I post my audio set up hoping I'm overlooking something that can allow 5.1 for all apps that offer Dolby Digital Audio.