I can't get Magnets to work with Limb IK

I am trying to get my character to pick up a piece of chalk. My puppet was one of the ones in the puppet library, so I didn't do the rigging myself, but I'm trying to learn based on watching videos and looking to see how this one is already rigged.

I made sure the chalk was in its own folder in its own layer in PS. I had to make a chalk tray on the chalkboard to make sure the chalk didn't fall to the ground. I have it set as Magnet, Dynamic, Collide, though I don't know for sure if it have the magnets set on the right folder entry. 

Next, I am trying to figure out where to put the Magnet on the Arm. I think I have all of the rigging right on the Left Arm, with the Left Wrist being draggable.

But every time I try to put a magnet anywhere on the Arm, I get the following error message:

If I put Dynamic on the wrist, the hand falls off. If I put Dynamic on the elbow, the forearm falls off. If I put Dynamic on the shoulder, the arm falls off. If I put Dynamic on the Torso, the entire body falls apart.  I have tried putting Magnet on the Hand in the Fist trigger swap set, but the magnet doesn't work there, either. I have no idea what to do anymore. All I want to do is pick up a stupid piece of chalk. Can anyone help me?

I'm on CH 25 (Build 46), using macOS 15.3.2