It's very strange. With YouTube app no problem LPCM, same for Disney+Saw the same but since a couple of weeks I mainly use the Shield because Kodi is way more customizable and I can also incorporate my music collection.
With Netflix when I am in the main menu and trailer are running (in French version) audio is LCPM but if I start the movie then switch to PCM ?! I try a movie in English and atmos is ok. It's look like Netflix French language is stuck in PCM. I am going to try if audio is LPCM with movie in English
At the end it's not a Stage problem at all