I first reported this behavior back in June of 2022. The same problem happens not only with Volume Up-Down but also with the microphone when you try to say a command. The only work around I have found is to unplug the TV from the wall for 10 seconds and plug it back in again, however if you launch YouTube TV again the problems will quickly reappear.
As I said in the original posting I believe this is a Roku App development problem. I believe the YouTube App is running too many threads at once or has memory leaks in the code, I'm not sure that the Netflix App has a problem unless YouTube was launched before Netflix.
I suggest that Roku Engineers test the YouTube App to see how many threads are running when the app is active. At this point there are 2 choices, either limit the maximum number of threads an app can run in the Developer Library and/or contact Google to see if they can reduce the number of threads the YouTube app is running. Like I said before Google may be polling your TV/Stick to snoop into your business.