Trying to troubleshoot an issue for my mother... Since she updated her iPad Air to iOS9, she has noticed that when she adjusts the volume using the rocker buttons on the side the usual display indicating the volume level no longer appears. She associates it with the iOS update, but she's also one of those people who is paranoid that every update is going to break something. So it's possible that the problem has existed previously and she just didn't notice it until now. The display does reappear when she reboots the device, but eventually the problem comes back. I did verify that she's using the cable and adapter that came with the iPad and not a third-party option. I also advised her to clean out the lightning port. Any other suggestions for a fix? Anyone else experiencing the problem?