Really odd actually. But unless the physical mute on/off button is defective, or you switch it on without knowing it, or you install an application to over write the physical mute on/off button, say from Cydia for example there is no way that the phone will auto on off mute/vibration.
I would suggest you to do a back of your files to iCloud and factory reset the iPhone.
The same goes to the alarm wake up, probably there is another app that's also set up to go off at the same hours even though you turn off one, the other still goes off, or there is another tweak force overwriting the alarm to stay on even though you turn it off.
Factory restore it to solve it, if your iPhone is not jailbroken.
You can later on restore you backup after factory reset.
03-02-2016 01:34 PM