If you've tried all the earlier tips, it never hurts to make sure that you're running the latest version of the iOS.
Nwelite na mbipute kachasị ọhụrụ nke iOS - Ọ bụrụ na ịnwalela ndụmọdụ niile dị na mbụ, ọ naghị ewute gị iji jide n'aka na ị na-agba ọsọ ọhụrụ nke iOS.