I have a 2016 Sharp 4k non HDR set, with a Samsung sound bar connected to the ARC HDMI jack. I added an Xbox One S, a year ago, and have been able to stream 4k from the Xbox Netflix, and Youtube apps with no issues. I purchased two new HDMI High Speed Certified cables, when I bought the Xbox. Last month I purchased a Roku Premiere. Using the other new caple, still in the unopened package, I got the HDCP 2.2 Unauthorised Content error purple screen. Spent a lot of time trouble shooting, with no solution. Roku Support said exchange the box, so I did.
Actually got the 4k Ultimate to try, same issue. Bought a new cable that actually said HDCP 2.2 on the box and tried that. Same issue at first, but after swapping inputs and multiple reboots it worked. For two weeks anyway, then the same problem. Swapping inputs and reboots, it again worked. The box failed again last night. I was able to again restore it. Roku support has been no help. Any ideas? Thanks.