I ' ve been experiencing the same thing . 7 Plus 128 GB running iOS 10 . 1 . 1 . Started happening in the past day or two . Random apps Google Photos , Facebook , others continually act as if I ' ve never logged into them before . Carrot Weather I use for an Apple Watch complication has my location as North Atlantic Ocean and the current tempforecast as 81 degrees F I ' m currently in Wisconsin where it ' s in the mid 30 s . and I always have Carrot set to Celsius . And ringtones were also reset to defaults . Probably some other symptoms as well that I ' m forgetting at the moment . Have no clue what could have caused this and yours is the first post I ' ve found of someone else reporting the same issue . Considering making a Genius Bar appointment after the holiday if it continues . Don ' t really want to try a full restore from backup as it ' s a hassle .