I totally agree it is a ROKU problem. I input a customer service request and every couple of days they ask if I am still having the problem. What a waste of time. I directed them to this post. Does anyone know if they have techs at ROKU.
I did the same thing with customer support, he kept going around in circles with me, then it was I will get back to you. Then i pointed him to this thread, and he told me it was my sound bar and he did all he could do. I disagreed and told him that, and that was the last I heard. I was hoping for a customer service survey, but didn’t get one.
I setup an entire AVR just for DD+. When I fired it up all I got was All Channel Stereo. I was pretty sad when I seen this thread. I was searching the interwebs and someone mentioned volume leveling.
I went into Vudu and played a movie that supports atmos (wonder woman). I hit the * button and turned off volume leveling. When the audio came back DD+ was enabled and working. Tested on Vudu, Disney, Netflix (didn't test Amazon, I assume its good now to).
I'm glad that turning off "volume leveling" worked for you; however, some of us have older units that don't support volume leveling so that has never been an issue for us.......none the less we still have the broken dolby problem.
P.S. You might want to be sure you are actually getting Dolby+ or other surround. Many AVRs will play 2.1 PCM stereo into all 5 speakers which might fool you into thinking that surround is working. Check your AVR display to see whether the INPUT is really surround.
This is the confusing part. My receiver shows Dolby Digital input but I don’t get anything out of the center channel. So, I think it pumps 5.1 digital audio (based on the Audio Setting on Roku, eg DD or DD+) into the receiver but it’s pumping in stereo to Left and Right only. This is my hypothesis.
Your AVR may be fooling you. Most AVRs display what you asked it to OUTPUT (e.g., "Dolby") even if the INPUT is stereo. Normally this is what you want since if you have a stereo input you still want it to play on all 5 speakers. You may have to dig deeper into your AVR to discover what the input signal actually is. Hint: if you see PCM coming from the Roku, that's almost for sure stereo.