It may be your tv but I can verify that it is an issue with HDCP. Like I mentioned I have my Roku Ultra plugged into a HDMI switch and depending on how the Roku is 'switched' in as the source the HDCP error message has appeared at least three times in testing. The purple overlay with only audio seems to occur when switching from HDMI 1 to HDMI 2 - Satellite to PC/Roku. In all instances video can be restored by either:
Restarting Roku - either unplugging the power adapter or system restart by menu if available.
Disconnecting the HDMI cable from Roku and reinserting it.
Temporarily switch the switch box off Roku to another source in my case PC then back to Roku.
This is an issue for me, I have tv with roku built in. I tried resetting roku video and audio but it did no good. And it's not doing it on all shows, I'm having issues on multiple streaming services but not all shows on those services. I'm incredibly baffled.
I'd be happy to take a closer look to see how we can help. I have a few questions to better understand the behavior you are seeing:
When did this issue first start occurring?
Which streaming channels are you experiencing this issue on?
What Roku model device are you using?
Have you tried removing the channel, restarting your device from Settings>System>Power>System restart (If you do not see a Power submenu, skip to the next step), then once it loads up again, adding the channel back once more to see if that clears things up?
What troubleshooting steps have you taken so far to try to resolve the issue?
With more detailed information, we will be able to assist you further.