Sounds to me like you got your tiller out of whack and let your nockset drift low. You wouldn't believe how screwed up your bow can be and still tune to a perfect 'bullet hole' if the tiller is whompyjawed.

That's the first thing I'd check. If tiller is not the same, top and bottom, then make it the same. Then reset your nock height and peep. If that's not it, then you'll need to look at cam timing. Do the easy stuff first though.