I recently got this iPad Air 2, and I've been noticing that every now and then I'll have to tap a button a second time because it doesn't act on the tap the first time. What's confusing me is that it is registering the tap. For example, if I tap a hotlink in Safari, I see the link highlight momentarily like it would if it was actually going to open, but instead it just sits there and I have to try again. Is this some kind of feature? I'm trying to make sure there's nothing wrong with the unit.