Not that it isn't possible, but string creep is something that usually will change over time, not all at once. What I would suggest is playing around with the draw length a bit. It could be that, as much as you try to use consistency in your form, the bow might be off just enough that your form does vary a little bit, even though you don't feel it. Try shortening it about 1/4" and see if this helps. If not then try going 1/4" longer and shooting for a while. Sometimes it only takes 1/8" to throw things out of whack. It's attention to details such as this that can make a huge difference.

If you mess around you might find what we refer to as "the sweet spot" and everything starts to gel real nicely. If you findit then that's when you dig out the tape and measure and mark everything on that bow so you can visually check for ny changes down the road, and know just how the bow was set up to your liking.