I'm experiencing odd volume issues with iOS9 beta. Unfortunately, I can't remember for the life of me whether or not they were present in iOS8, but I'd be interested to hear if anyone else has had similar problems in that version... Occasionally, the max volume of my iPhone is significantly reduced. You can whack the slider all the way to the right and it simply isn't as loud as it should be. Restart the phone, and the volume returns. Has anyone else experienced this? I think it might happen when I switch from using bluetooth headphones to wired, but don't take my word on that.