Hi! My iPhone 6 plus has been exhibiting random vibrations that cause the phone to display the Mute icon every now and then. The mute switch works just fine, it's not loose in any way, and I keep the phone in silent 99% of the time. Tonight, when I was using the iPhone with Sleep Cycle under my pillow, whilst the iPhone was in Do Not Disturb mode, it showed the Mute icon again when I picked it up to check the time, even though it was on silent. Just now, when I was walking, it also vibrated without a reason, and no, I don't have any rogue notifications, push e-mails without a badge etc. that could cause that. The repair guys suggested I do a system restore and set it up as a new iPhone, but this obviously didn't help. It already laid in an Apple Certified Repair workshop, where they just put it on a desk and it did nothing for a whole week, and now I have it back, since it didn't occur while it was in their hands. Has anyone had something like this happen? Do you have any ideas how I might invoke this behaviour so that they actually take it in and exchange it?