I have a Galaxy Tab 3. Lately I've been having an issue when I have Spotify open and my tablet goes to sleep, my tablet will turn off. I open the app, let my tablet turn off and then I'll press either the home or power button, nothing happens. I have to hold the power button for about 10 seconds and them it will turn on as if my tablet was turned off. I've done a factory reset and also reinstalled Spotify. Still having the issue. Any ideas as to what's going on? Thanks in advance.