So I bought a TCL 65R625 and hooked the PS4 directly into it in order to get access to HDR. I then routed SPDIF audio from the TCL back to my receiver. However, I quickly noticed surround sound was being down-mixed to 2-channel stereo when I tried to watch a Blu-ray movie. Further, the 5.1 surround sound icon that shows up on Netflix in the PS4 was completely missing. When I hook the PS4 directly to my receiver (Sony STR-DH520) I get surround sound no problem. I've contacted TCL tech support, and they had me try using HDMI "ARC" and setting the audio output of the TCL display to "Auto Pass-through". Unfortunately, I get the same result: 5.1 icons missing and only 2 channel stereo. At this point, I have to believe the PS4 is intentionally doing this as some sort of anti-piracy measure. In other words, it doesn't recognize the TCL display as a valid device, while it DOES recognize my Sony Receiver as one. The only reason I have to connect my PS4 directly to my TCL display is so I can get access to HDR features (my receiver doesn't pass the PS4's HDMI 2.0 check).
By the way, even when my receiver shows a 5.1 grid coming from the TCL display, the audio from the PS4 is still down-mixed to 2-channel stereo.
