I recently bought a Samsung NU8000 Smart TV.
HDMI 4 is ARC capable and I connected to my Yamaha RX-V473 HDMI out (ARC Capable)
After few days trial and error here is what I concluded
If I remove my HyppTV and Android box from V473 or TV, I have 100% success rate
If any of my HyppTV and Android box connected to TV or V473, I only have 80% rate. Yes, it work 2 out of 10 times. TV is detected my ARC and v473 but the audio just didn't play through my V473.
It is how ARC work?
ARC Audio Return Channel