I noticed a few weeks ago on a flight that my top volume button became really "soft". It would register when pressed but there was no "click" feedback. It was hard to tell if I really pressed it unless I looked on the screen for the volume indicator. I planned to go to the Apple store to get it looked at but after a day the button started to click again. I was about to brush it off as a one time thing but I have taken three more flights in the past couple weeks and I experienced the same issue on each of them. The top volume button gets really soft and loses its clicky feeling/sound. A few hours after landing the button returns to normal. Anyone else experience a similar issue? I'm wondering if this is due to the sealing of the phone for the water resistance. I know there is a pressure equalization valve in the phone to deal with elevation/pressure changes. Maybe the valve cant keep up and it's affecting the gaskets on the button.