I am doing simulations of powder compaction using artificial gravity. I have been simulating them under 2000g. So once this gravity is applied, particles start to disappear as in the screenshot attached. You can see that number of particles reduced from 7884 to 7508 and then it stays constant. Reducing the time step from 1e-6 to 1e-7 seconds has increased the final number of particles, but only slightly, so some particles are always disappearing.
I wanted ask is the problem only in the time step size? Do I need to reduce the time step further? The input file is also attached
EDIT: added the latest versions of files that worked for me