Very new to the Home theatre scene.I have a second hand Onkyo TX-NR515 connected to my Samsung 65in 4k via eArc. When watching Netflix, Amazon etc I sometimes have a slight dropout in audio.It happens for literally half a second and returns to normal. I've tried Auto and Pass through on the TV with no luck.PCM is fine but am I correct in assuming this drops the audio to a 2.1 ? My setup is 5.1 running 6ohm speakers. I calibrated and updated the amp's firmware via USB. Am I missing a setting on the amplifier ? The front panel, usually displays ARC, Dolby plus which is probably the best I can get out of the setup.I ran through the Onkyo menu multiple times, but I cannot find anything obvious that i need to change. Any help would be appreciated as this problem, albeit a small issue is quite noticeable when you're waiting for it to happen again through a movie etc.Many thanks everyone for any replies.