Atom lost across periodic boundary despite low speed

input_C_N2_equlibration.lammps (1.4 KB)
input_C_N2_shearing_test_moving_wall.lammps (1.8 KB)
LAMMPS version: LAMMPS 64-bit 2Apr2025 with GUI
Operating System:Windows 11

Hi all, I am trying to do a smiple simulation of a sheared fluid. I first run the equlibration process which executes fine, then for a test I tried shearing, where I simply set wall velocities and let the simulation run.
However, no matter what I do simulation crashes after few steps reporting lost atoms. I have checked on VDM animation that the particles do not seem to cross the z boundary, the only non-periodic one. I do observe wall atoms crossing the periodic x and y boundaries. The velocities also do not seem to be too high in the system.
Maybe im applying the conditions wrong? My goal is to have a fluid between 2 layers of graphene that are moving at constant speed.
Any help would be appreciated!