I have the new P-07 and this decocker separates in the middle. My P-09 is glued together.The following is a post from JoeL:
See the part that is against the right edge of the decocker spring? The one that you have to hook the decocker spring under? That piece has moved to the left on the shaft, toward the spring. Take a small flat bladed screwdriver and push it to the right (based on the view in your photograph) until it hits the shoulder to the right. That little piece has moved too far towards the spring and that is why your decocker doesn't work.
Move the circled piece to the right from the view in this photograph. Compare to yours and you will see a gap between the circled piece and the shoulder on your shaft.
I put the decockers back in both my guns today. One of my decocker shaft assemblies did exactly what yours did.