[vitocorl]

Is the missing auto framerate switching Feature a known "Issue" for the Android TV Netflix App?

Use the Kodi Leia Netflix Addon if you want such a feature on the 2016 Mi Box. Kodi can then also work around the 5.1 DD+ audio dropouts by transcoding such audio to 5.1 DD. 

I tried to do that, disabling DD+output in Kodi, but Ampli shows PCM. What am I missing please? And I have to select each time language preferences. 

Have you enabled Dolby Digital transcoding?