particles passing through plate in compression simulation

Hello,

I am a new user of LIGGGHTS. I am trying to perform a compression test with a cylinder being pushed into a bed of particles, and plot the force acting upon the cylinder. However, I have noticed that my particles are simply passing through the mesh, and all the forces being outputted are 0. I am not sure what is going on - I have tried to fix this by decreasing the timestep and moving the mesh slower, but nothing has worked. I've attached my input scripts. Does anybody have an idea as to what may be causing this?

Much thanks,
Pearl