Helping my mother here...she has an iPhone 6+ and when it is in sleep mode for a few hours and then awakened, the keyboard click sounds and the sleep button sound are silenced for no reason. The speakers work just fine and the ringer and text message sounds continue to work. In the sound setting, the lock sounds and keyboard clicks are still activated and the sound is turned all the way up. To get the sounds back, there is no rhyme or reason to it....I reset the phone with the home button and sleep button or turn the phone off and back on again and sometimes it gets the sound back and sometimes not. Anybody else experiencing this? And any recommendations? Should I take it back to the Apple Store and get her a replacement or is this some sort of bug that will iron itself out with a future update?