Let me add my voice to the list of display bugs in 8.0.
I have a Sony XBR43X800E which is capable of 4K HDR@60hz. That was what I was successfully running with Roku FW 7.7. When I upgraded to 8.0, all that will work is 4K HDR@30hz. If I set the HDMI enhancement to on on my display, the display goes black, and will not let me set 4K HDR@60hz, no matter what I try. All my cables are HDCP2.2 and all was working fine prior to 8.0. I'm currently forced to run the Roku at 4K HDR@30hz with v8.0 FW. Hope this gets addressed soon.
Roku Ultra, Roku 4 Internet:1gig/40 Time Warner Spectrum Gigabit (DOCSIS 3.1) Cbl Modem:Technicolor TC4400 Router:Asus RT-AC5300
My Sony XBR TV is working fine with HDMI enhancement turned on and with Roku Display type manually set to 4K HDR at 60Hz. On my Sony TV only HDMI inputs 2 & 3 support 4K 60p. The only Issue I am having is when the Roku Auto-adjust display refresh rate option is enabled. There is a problem with auto adjusting the content's native format causing a sync issue between the Roku and TV. This option is disabled by default.
I'm experiencing a problem similar to Mike1597. My Samsung TV is fine with the Roku set to 4k HDR 60hz. All my inputs support 4k HDR 60hz. The only problem I have is with the auto refresh option enabled on the Roku. It causes an HDMI handshake sync issue and even a few times made me have to reboot the Roku so I could watch video again. I set it to disable and everything is working fine now.
4K HDR TV: Samsung UN60KS8000 4K HDR Receiver: Yamaha RX-V381 4K HDR blu ray: Samsung UBD-K8500 4K HDR streamer: Roku Ultra 4640 (2016 model) 4K HDR Gaming: Xbox One X 4K HDR DVR: Directv Genie HS17-500 w/ C61K mini client Cables: Amazon Basics 18Gbps HDMI
Toggling the color subsampling setting between 4:2:2 and 4:2:0 doesn't help at all, btw. It is true that they brought this setting out of what was a secret menu in previous firmware releases to the main menu now, but neither setting works for me. In the previous firmware (7.7.x), I had mine set at 4:2:0 for stability and all was fine.
As others have mentioned, I'm reduced to watching 4K HDR 30 vs successful/stable 4K HDR 60 with previous 7.7.x firmware. Of course, that rules out watching Netflix HDR titles, as they are streamed in 4K 60.
Same issues. 4K HDR 60hz worked fine before. Now, two thirds of the time I turn my Roku on it just goes to a grey fuzzy screen. When it finally loads again, I switch it back to 4K HDR 30hz or just standard 4K 60hz, and the problems stop... but switching back gets me to weird grey static screen.