I have a Denon S950 which supports DD+ but all I can get is roku to send PCM. I have tried everything, is this a limitation of roku? I have tried an roku ultra and brand new roku steaming stick+ same results.
I had a similar issue on my 4k stick, with it only streaming stereo. I couldn't find anyone that managed to fix it so out of desperation I did a factory reset on my Roku and it seemed to fix it even though nothing changed as far as the software version or firmware update went. You might want to give this a try but only if you remember all the app passwords you are using.