Why does my snap chat notification turn itself off?

[AC Question]

I know where to turn my Snapchat notification sound and vibrate on, and it works for a couple hours and then it stops... When I go into the menu again, the sound and vibration boxes are unchecked! So annoying. I've deleted my Snapchat and brought it back. It has done this on both my Samsung S4 and Samsung S5. Brand new phones. It just doesn't seem to matter how often I go select them again, it just never lasts. I want my notification sounds...