Puppet Pin Suddenly Unavailable

Hi everyone, I've tried searching in the forum and youtube and didn't find any solution to this.

So I was making an animation with puppet, it all works nice and well. No sort of problem. A week later, the client asked for a change, so I reopened the After Effect file, and found that one of my composition lost the pin. It is greyed out in the composition:

Also, the mesh position also shifted to a different place.

As you can see, the mesh is now on the top left of the composition, not in the actual image. I can still create new pins in the mesh in the top left, but it doesn't affect the movement of the image. Why did this happen and how can I fix this without redoing the entire composition?