Roku support asked me to upgrade code, I did that, and put the audio back to default, and everything appears to be working ok. The Roku is sending my AV unit dolby atmos all the time though, even on stereo tracks, so I guess that's how it's designed. Roku support is closing my case, so I guess they knew what the problem was and have fixed it with the latest update. Anyone having issues might want to try updating the software.
1 Auto Detect. where the Roku will modify all audio to be the highest possible type audio your connected device will have and pass any audio that matches that type. This can make things sound odd as not everything sounds appropriate upscaled to that max.
2 Audi passthrough. which will pass all audio to your receiver in the format it is received. This allows your TV, AVR, or sound equipment the ability to process it accordingly and be best for that format.
3 PCM Stereo. which will pass any PCM audio and downgrade all other Audio received to PCM Stereo before sending to your other equipment.
Our preference is Passthrough (just like our previous Roku models).
Which OS is yours running. Ours was still OS9.3 and has the audio Popping/thumping sound when switching Audio Types.
I just tried this and did not help or update the system
last update was Oct 22 and checked today Oct 27 right now and said no updates available
still having dropouts etc. on Auto and always claims to feed Atmos to the AVR even on non Atmos content and in passthrough always just feeds 2.0 stereo clean with no dropouts but no DD surround on any content whatsoever
not the way it is supposed to work or advertised..
Also I believe that one needs AutoDetect and not passthrough to get Netflix in Dolby Atmos when available, because on NF the first device in line needs to decode Atmos for it to recognize it
so if the audio isn't clean and clear and in the correct codec to the AVR on AutoDetect, and one uses passthrough, then one is going to have to switch back and forth settings with and without Atmos on NF, assuming of course that AutoDetect works at all which it doesn't appear to be doing now
and for me passthrough is only producing 2.0 stereo no matter what which is not acceptable either or the way it is supposed to function; it should passthrough untouched and undecided whatever bitstream is input into it in that setting (that is what "passthrough" implies at least).
Auto detect and passthrough both give me Atmos on my Anthem preamp. The difference is that detect makes everything Atmos instead of mono, stereo, 5.1, or 7.1 - though I have only tested stereo and 5.1 at this time.
OK so at least some people are having success with passthrough
a) How are people getting OS9.4 installed? Mine is still saying no upgrades available and is still in 9.3.1
b) What source material and on what channel did you verify that passthrough was passing 5.1 and not only stereo so I can try and match that exactly if possible? Good to know that it is nothing to do with the Anthem; you probably have the same preamp section on the AVM 60 as is on the MRX 720 so that eliminates the only other suspect component in the chain, which is good.
I'm still on 9.3.1 as well and I get 5.1 on Vudu, Netflix, and Amazon. Lots of movies on Vudu as I wanted to be sure it decoded 5.1 even with a few old catalog titles that are still DD instead of DD+. The Amazon and Netflix stuff was just whatever came up that wasn't Atmos.