I recently purchased a Roku streaming stick+. It is run into my TV (a ~8 y/o panasonic plasma), with an optical audio out from the tv to my receiver. The TV is able to pass a dolby digital signal through the optical audio out (verified in TV manual: https://shop.panasonic.com/support-only/TC-P55ST50.html). I have dolby digital turned on in the Roku settings, and have checked to make sure that volume leveling and night mode are turned off. I have also tried numerous channels but the receiver is only getting a 2 channel PCM signal. Any thoughts on why this may be happening or any other settings I need to check?
I just had this issue. A Roku streaming stick 4K plugged into my LG 4K TV then using optical from the TV to the receiver as the receiver only supports HDCP 1.4. This setup has been working fine for months. Today I could only get stereo out. Tried plugging the stick directly into the receiver with the same result. Audio settings were correct everywhere. Tried toggling every audio setting I could think of. Nothing worked.
The solution turned out to be I had to go into system then advanced system settings and then advanced display settings. I set auto adjust display refresh rate to disabled. I had previously enabled it. Also HDR subsampling I had to set it back to 4:2:0. I then tried streaming content and surround sound was back! I then went and put back the settings and surround is still working.
Most streaming content is in DD+ these days but optical can only carry DD 5.1. Some older TVs will not do the conversion. I think a few of the roku models have a way to limit output to DD 5.1 in their settings.