My 6s, which is restored and set up as new on ios 9.3.5, sometimes reloads apps out of nowhere. Common apps like facebook, instagram, reload when I exit or launch another app and usually there is only one or maybe two apps in the multitasking tray. For example: I m on facebook, I go to the homescreen and open instagram, 10 seconds later, facebook reloads. I have only one game opened, like Riptide Renegade, I lock the phone and after two minutes the game reloads.