no sound

After all the problems I've had with the streaming device, I finally got one that works perfectly and has done so for weeks, so I want to avoid sending it in.  Here is my problem.  Amazon Prime and Showtime keep losing sound.  Not on everything, but it usually means I have to use the reset button.  I'm not sure if it is on all of Showtime or just the app.  It would be a minor annoyance, but it takes so long to reset, and I had to do it twice today.  I've tried completely unplugging device then reset and did not help.  I thought I could just leave the device on all the time and just turn off the TV, but when I turn off the TV the device turns off as well, even though I used the TV remote to do it.  Has anyone else experienced something like this?