My Roku Ultra worked fine from May 2021 through around October 2021. Now it brings up an HDCP Error 020 more or less the first time I try to use it each day. Going through the steps on the screen (unplug, etc) works for a while, but then the error comes up again ~the next time I use the TV (Vizio). I've tried different ports. I bought a new HDMI cable that's rated for 4K. I'm using the correct HDMI port (ARC), though I've tried other ports as well.
I don't want to share all my device info on the public forum, so Roku support, please private message me so we can get this fixed.
Roku operating system version 10.5 added added a new "Power" item in the "Settings > System" menu for some of the latest Roku models. The new "Auto power savings" item there will put your Roku device into a low power standby condition after a period of inactivity, such as when your tv has been turned off for a while.
Pressing a Roku control key on your Roku remote (not Power, Volume, or Mute which act on the TV, not the Roku) is said to bring the Roku out of standby and back to full operation. Pulling the power for a few seconds to restart the Roku will restore full operation as well.
I supect this standby state is the cause of your problem.
If you have a "Settings > System > Power" menu item, deactivating any power saving options you find under "Auto power savings" will prevent your Roku from going into standby in the first place.
Thanks @makaiguy I'll give that a shot over the next week or so and report back if it works.