I bought the TCL Roku TV with 4K and HDR (55S401) about a year ago, and so far I am pretty impressed with how everything looks. I got an Xbox One S last night and was shocked to see that it's not detecting the TV as a 4K display.
Not only that, when I set the video settings on the Xbox to Auto-Detect, I get stuck in 640x480 resolution. I can only go to 1440p if I force it in HDMI mode instead of Auto-Detect. However there isn't an option to force 4K resolution. And on top of that, I tried putting on a Blu-ray DVD in the Xbox and it gave me the pink/purple screen HDCP error.
I set all my HDMI ports to HDMI 2.0 in the 'TV INPUT' menu, and I tried each port (1, 2, and 3) but that didn't work. I've also factory reset the TV twice and updated software to 8.2 build 6170.
I've also tried several different processes of power cycling and plugging in the HDMI cable in different orders with no effect. I am using the brand-new HDMI cable that came with the Xbox, and I tried another one that I had and it didn't work either.
I've called Roku support but they weren't able to help me. From what I read on other forums, I think it's a problem with the HDCP hand-shake or the EDID not being sent from the TV. If anyone else has had this problem please let me know. It's extremely frustrating to find out this awesome TV might be defective.