Powernode & Apple TV all kinds of audio output issues

Hi there,

I have quite some issues when using my Powernode 2i in combination with my Apple TV 4K (no optical port otherwise this post wouldn't have existed)

Behaviour is quite unpredictable in terms of what output the Apple tv uses depending on the specific app I use, being Youtube, Netflix, Ziggo and/or NPO (dutch local broadcaster). 

Ive tried several options also connecting both Apple TV and Powernode with ethernet cable as well as using the bluetooth speaker option, but im constantly running into vague speaker output issues. It differs from App to App. Youtube and a local Dutch broadcaster called NPO seem to work fine, but with Netflix when using Airplay, U2 pops up again and wile using the Ziggo app it says its connected to the Powernode (airplay) but it plays over the HDMi cable (which in my case is connected to a beamer with a very lousy speaker in it)

Im trying out so many things that im getting more confused every new round of efforts.

I gave my Apple tv a fixed IP adres as I read somewhere that could help. Currently the Powernode is connected using Wifi and the Apple TV through wifi as well, though ive tried all of the combinations. 

I tried closing other apps that output audio before starting a new one.

I think im at the current conclusion that for some apps I can use Airplay, whilst for others (Netflix and Ziggo) i need to connect to the Powernode with Bluetooth.

Does anyone have a clues/guidelines on using the Powernode (or another streamer) as main speaker output icw the Apple TV and the different Apps/broadcasters on the Apple TV?As in what are the best outset configurations in terms of; Wireless to Router or WiFi? And when using WiFi any advantages of 2GHz vs 5 GHz or the other way around? 
Even when both connected through Ethernet in some cases I experience some nasty audio glitches (clicks..dropouts.. every couple of seconds...i dont know how to describe best) but still need to determine when exactly that happens (in bluetooth/airplay/which app on apple tv specifically if so..) 

Any tips and/or guidance is greatly appreciated.

Best regards, 

Matthijs