Slightly off topic, but where are you getting the Amazon Music app from? Doesn't seem to come preinstalled, and the apk I tried downloading didn't work.
It doesn't matter though since it cannot do Atmos apparently, I will not be using this device for Amazon Music. I deleted the app.
Do you use another device for Amazon Atmos music? I yes, which one....and does it play Atmos at very low volume compared to stereo?
I know, I just wanted to know, what happens with regard to the very low volume for Atmos tracks, if you cast them from your Android app to the Fire TV stick. Are the much lower compared to stereo in this case, like on my Cube? An what about the volume, if you play Atmos tracks directly on the stick, without using the Android phone. Are they as loud as stereo tracks?
In my experience Dolby Atmos tracks are pretty much always lower volume regardless of device. This is by design. https://www.travsonic.com/why-dolby-atmos-is-quieter/
On the phone app when switching back and forth there is a big difference in volume levels. Unless you use the volume leveling option in the settings and then they are similar.