Just received my iPhone 6S and I've noticed a strange behavior that wasn't present on my old iPhone 5. When pressure is applied a little below the Apple logo on the back, the case makes a "pop" or click noise. Doesn't happen every time, but after the phone has not be used for a bit, it will produce the sound. Having been on the 5, I missed out on the clicking/popping screen issue that was present on the 6. Anyone else experiencing this minor annoyance?