Solving playback issues

[Generationgav]

I just bought a Roku 4k streaming stick due to a few issues with my Fire TV stick and wanting BBC iPlayer UHD which the Chromecast simply doesn't support.
I've got a Sony 900F and a Denon 2300W. All support HDCP2.2.
However I've not been able to play anything at all yet as the Roku immediately throws an HDCP 020 error. It also can't detect the TV at and saying it's 720p, although changing it to 4K makes it output 1080p.
I've tried multiple ports on the Denon, it's directly into it.
I've not been able to try it directly on the TV as the TV is wall mounted, but I know all my cabling is OK as I run a Chromecast Ultra, Fire TV stick, UHD Blu-ray player and Xbox and never once had a handshake issue like this.
I think it's going to have to go back, but wanted to know if there's any other suggestions first. I've also rebooted everything multiple times.

I have seen this thread - but there appears to be no solution. I've checked everything in that thread to no avail.

https://community.roku.com/t5/Solving-playback-issues/HDCP-errors-with-4K-Streaming-Stick-via-Denon-...

[RokuTakashi]

Hi, @Generationgav

Thanks for reaching out here in the Roku Community.

We acknowledge your concern, and we;d like to assist you regarding the HDCP error on your Roku Streaming device. Rest assured that we're here to assist. As a start, we recommend visiting this support article on What should I do if I see a “HDCP Error Detected” message or a purple screen?

This article provides guidelines and troubleshooting steps to resolve the HDCP error.

Please keep us posted on how it goes, and we'll continue to assist further.

All the best,
Kash

[Generationgav]

Thank you.

I've already tried everything I can in that article.

It's the streaming stick, so no cable.

I can't plug it directly into the TV easily, but wouldn't help anyway as it's not how my setup works.

Everything supports HDCP 2.2 and everything else works! 

[RokuJanadeeK]

Thanks for keeping us informed, @Generationgav.

We're happy to continue assisting.

Would you mind specifying the troubleshooting steps you have taken so far besides the one you mentioned in your previous post? Have you tried using different display settings on your Roku player? How about switching HDMI ports?

Please keep us updated.

Regards,
Janadee