passcode changed itself!!!
I always use a 4 number password on my 6plus. all of sudden it happened, the passcode become 6 number one afternoon when I use (5mins before it still OK, 5 min later become 6number). I never change it, and no one else did it (it`s with me,and no one know my passcode). I have no idea what is the 6 number passcode. I can only use touch id to login.
iPhone 6 Plus, iOS 9.2.1