Minecraft lock up bug

Whenever I leave Minecraft running on my iPad and I turn the device off, when I turn my iPad on unlock it, it is completely frozen. I have to restart my iPad to get it to unfreeze. If I double tab the home button and swipe up to close a Minecraft and then turn my iPad off, then it does not freeze up. It only freezes up when I do not close the app and I turn my iPad off.