I’m using the current version streaming stick 4K plugged directly into a 1080p tv. Everytime I turn on the tv and try to stream on Paramount+ i get HDCP error 020. (Audio but no video) once I reboot the stick everything works fine. I have the resolution set to 1080p and not auto and auto refresh rate is disabled. I don’t know if this happens with other apps. I haven’t been using anything else.
See if you have a "power saving" option under Settings->System->Power and disable it if you do to see if it helps. Not all Roku devices have that option, but it is known to cause problems with some TVs.