I have my Roku Ultra 2020 connected to Oppo 203 hdmi input. I do this since my receiver doesn’t support 4k pass thru and if I connect to my LGE6 tv, I don’t get surround sound back to my receiver using optical out. ARC doesn’t work.
Everything was working fine but lately if I turn on the Oppo and switch to its hdmi input, my tv doesn’t see a signal. I have to unplug the Roku and plug back in and then we are fine. Why is the Roku turning off? I assume because the Oppo has powered off? The Roku itself has power always on.
is there a way to keep the Roku active without keeping the Oppo powered on? The Oppo is on standby.
That TV ARC/Optical & potential transcoding issue sounds odd (you should spend some time working that out - sounds like a Simplink/Audio settings issue - if its just with the 4800 that you experience it you may want to change Settings/Audio/HDMI=Dolby Digital when you connect it to the TV).
Are you sure the Roku is powered off? Sounds more like a loss of HDMI sync (HDMI handshaking issue).
Try manually configuring Settings/Display type=4K DV TV (or 4K HDR TV or 4K TV, if the 30/60Hz issue applies).
You stated you had a "Roku Ultra 2020" - that's a model 4800.
You should check your model # and firmware version: Settings/System/About
Your E6 should be able to pass DD via ARC/Optical from both internal apps and connected devices without issue - if you cant there is a configuration issue in the TV's Simplink/Audio settings or the AVRs CEC/ARC settings, or both (or a bad/unsupported cable).
Not all HDMI devices/ports are equal, and not all HDMI handshaking sequence results are the same, so you could very well get different behavior with the Roku connected directly to a TV/AVR.