Disappearance of inserted particles

Hello,

I faced a problem when running the CFDEM coupling: my particles disappear after leaving the insertion volume. My geometry is a simple rectangle, and I wrote the LIGGGHTS code such that particles are continuously inserted from one face of the rectangle. When I run the LIGGGHTS code alone, no problems occur, and the particles do not disappear after leaving the insertion volume. However, when I run the CFDEM coupling, the inserted particles disappear after leaving the insertion volume. I would be grateful if you could provide any advice on how to solve this problem.

Regards