Mesh separates from collider

I was using Isaac Sim to add pedestrian in the scene, but I found mesh separates from collider. So the lidar could not detect people. How can I sovle this issue? Thank you

Does the lidar detect the people if you add a collision mesh to them?

Actually, the collision mesh exists, but it could not follow the people skeleton. And when I clicked the moving pedestrian, no Xform could be selected.

here is my demo usd file, my isaac_sim version is 2023.1.0 (35.7 KB)