Did you recently install/uninstall something? Try reinstalling/uninstalling the 'suspect' program. Also, you could try a System restore to a point before you had the problem (but don't try this unless somebody else confirms it as well!).
Best phone camera 2017
Stunning new film posters by Hattie Stewart, Joe Cruz & more
iPad Pro 10.5in (2017) review
28 astuces pour profiter au mieux de votre iPhone