AAC 5.1 being down converted to PCM stereo by Roku Ultra
I have a Plex server on my Synology NAS and when I try to play back movies the AAC 5.1 audio (from Handbrake) is being down converted to stereo. Netflix plays Dolby Digital just fine so I know the audio set up is fine.
I thought the Ultra was supposed to transcode AAC 5.1 to AC3 5.1. I believe all my settings are correct on the Roku (which is attached to Yamaha AVR by HDMI).
Also, if I encode the movies as AC3 they AVR plays the Dolby Digital 5.1 just fine. Do I need to redo all my movies or is there hope?