Particle 151 had a negative distance to a lattice boundary

hello everyone! Hope everything goes smoothly!
I am a beginner in OpenMC. I defined a lattice material in a sphere and set up a fixed source.
Edit: I suspect there may be an issue with the settings of the source. What I want is for the source to function as a disk, with the disk surface parallel to the lattice surface, as shown in the diagram,

But I got an error while it was running, as shown below:

===============>     FIXED SOURCE TRANSPORT SIMULATION     <===============

 Simulating batch 1
 WARNING: Particle 151 had a negative distance to a lattice boundary
 WARNING: Particle 376 had a negative distance to a lattice boundary
 WARNING: Particle 278 had a negative distance to a lattice boundary
 WARNING: Particle 76 had a negative distance to a lattice boundary
 WARNING: Particle 326 had a negative distance to a lattice boundary
 WARNING:  WARNING: Particle 101 had a negative distance to a lattice boundary
Particle 26 had a negative distance to a lattice boundary
 WARNING: Particle 1 had a negative distance to a lattice boundary
 WARNING: Particle 452 had a negative distance to a lattice boundary
 WARNING: Particle 354 had a negative distance to a lattice boundary
 WARNING: Particle 301 had a negative distance to a lattice boundary
 WARNING: Particle 401 had a negative distance to a lattice boundary
 WARNING: Particle 430 had a negative distance to a lattice boundary
 WARNING: Particle 130 had a negative distance to a lattice boundary
 WARNING: Particle 252 had a negative distance to a lattice boundary
 WARNING: Particle 51 had a negative distance to a lattice boundary
 WARNING: Particle 478 had a negative distance to a lattice boundary
 WARNING: Particle 227 had a negative distance to a lattice boundary
 WARNING: Particle 203 had a negative distance to a lattice boundary
 WARNING: Particle 176 had a negative distance to a lattice boundary
 WARNING: Particle 153 had a negative distance to a lattice boundary
 WARNING: Particle 187 had a negative distance to a lattice boundary
 WARNING: Particle 481 had a negative distance to a lattice boundary
 WARNING: Particle 328 had a negative distance to a lattice boundary
 WARNING: Particle 483 had a negative distance to a lattice boundary
 WARNING: Particle 454 had a negative distance to a lattice boundary
 WARNING: Particle 28 had a negative distance to a lattice boundary
 WARNING: Particle 404 had a negative distance to a lattice boundary
 WARNING: Particle 134 had a negative distance to a lattice boundary
 ERROR: Maximum number of lost particles has been reached.
Abort(-1) on node 0 (rank 0 in comm 0): application called MPI_Abort(MPI_COMM_WORLD, -1) - process 0

This is my script,
test.ipynb (165.3 KB)
Looking forward to suggestions!
Best regards.