Apple TV no sound on some apps

I have an Apple TV 4th Gen. About a month ago we noticed that YouTube videos go black for about 5 seconds before starting, and in less than an hour lose sound. When this happens, HBOmax, Hulu, Prime Video and other apps also lose sound. A hard reset fixes the problem. But at this point we’re having to do a hard reset everyday. Apple is connected to Samsung TV via a Yamaha receiver. Any suggestions?