The problem has now spread to Prime Video channel. The step to produce it is to press play or select the show or clip. I'm not pausing them. I've gone through the process of removing and installing Prime Video again which did not fix it.
The clips on Youtube vary, it isn't from one channel or creator on that app. It isn't happening on all content not even most of it but it is generally occurring more than once each time I use the channel which is everyday several times a day.
As to Prime I was watching a program on that earlier today with no issue. Now, I've tried 5 different programs and none of them have sound although the one I didn't finish earlier still has sound.
I need to add that all of these clips or shows work fine through the same streaming sources through the Samsung TV and the problem is just audio not issue with video through the Roku.