I didn't notice this behavior the first couple days of owning the phone, however during the last 3 days or so, I've noticed that if the phone has been sitting for a little while, when I first double tap the screen on, the lockscreen will be unresponsive for a couple seconds before I can unlock the phone. Once the phone is running normally, the lag goes away. Anyone else notice this? Any fixes? It's a little annoying for such a flagship phone.