Hi guys, I tried iOS 9, and I didn't like it, so I restored back to iOS 8.4. I tried just plugging the 5S to mac, and pressing restore (no backup), and I also tried the home button pressed and connect, and restored that way too. But It seems like some of iOS bugs remain after I'm back to iOS 8.4. First, my mute switch isn't working. I actually got my phone battery replaced when I was on iOS 9 public beta 3, and when I got the phone back from repair shop, the mute switch didn't do anything. My CC said rotation lock, so the mute button should be actual mute button. Then, I don't know if this issue was from iOS 9 as well, but I'm on iOS 8.4 without restoring backup, and if I open ANY app, like settings, if I do a quick scrolling down right after opening Settings, it doesn't respond for 1 second (freezes), then scrolls fine. It's just anytime app is launched, it does this. Once I'm in the app, whatever I do, it's responsive. If I press home button, home screen is responsive too. It's just when I open any app, right away, it freezes for 1 second. I doubt this has to do with battery replacement. This doesn't sound like a hardware problem to me. However, no matter how I restore my phone back to iOS 8.4, these two bugs don't go away. Also, the mute switch bug, I don't know if you guys with iPhone 5s have it, but some others also has it. Please see here: https://forums.developer.apple.com/thread/6617 Could someone please help me?? How do I do a complete 100% new install of iOS 8.4? I used iTunes on my mac, but do I have to redownload the iOS 8.4 file by deleting it from iTunes? Thanks so much, and eagerly waiting for your reply..