Surround Sound Problems
I started noticing that a large portion of my library has some issues playing back media when NOT using my surround sound system. This always worked in the past, although I recently updated to Android 7 (from 6). My setup is as follows: a Nexus Player connected to a Marantz NR-1403 Receiver, which is then connected to my LG 47LV500 TV. Typically, I don't actually use the surround sound and set the Marantz' standby connection to route directly to the TV. For the past several years this has worked fine. With the receiver off, I would watch Plex and the TV would output transcoded stereo. Now, however, when I try to play content this way, I get a generic Plex failed to play this media error (not sure offhand of the EXACT message) but I didn't see anything in the logs related to it.
After messing around with the config somewhat, I found an option the Android TV settings for Sound, called Surround Sound. It was set to "Auto". I noticed that when I change that setting to "Always", the content will play fine, but every few minutes there will be some audio distortion. It's better than not being able to watch things at all, but ideally I'd like it to function the way it did on 6.0. I'm thinking about downgrading and figuring out a way to block future updates to the OS, but before that wanted to see if others came across the same issue and had a better solution.