I managed to get surround sound when watching movies with kodi. There was a pass-through and stereo up mix setting that I enabled. It sounded a bit off but I think it's still better than the 2 channel sound it was outputting.
There are no audio settings that I can find anywhere in Netflix or Amazon prime unfortunately.
This is really annoying that it's so difficult to get it to work.
I contacted the person I purchased the android box from, maybe they can give me some answers.
Thanks for all of your help