Nvidia Shield - Constant audio desync, video stutters/pixelation/tone mapping issues

Maybe its the new Player from v9.29+

So please try Version: 9.28.0.3162 from Apkmirror.

com.plexapp.android_9.28.0.3162-868271524_minAPI21(arm64-v8a,armeabi-v7a,x86,x86_64)(nodpi)_apkmirror.com.apk

How your Sonos Arc play DTS-HD?

HRA only works with Shield Update v9.0+