A question related to Lagrangian_Particle_Tracking

I want to know why the particle don’t move after a certain time in the simulation process, eg. when the Julian day to turn on particle tracking is 212, the Julian day to turn off particle tracking is 277, at the same time, the Julian day to start seeding the particle is 212, the Julian day to end seeding the particle is 277, but the particle don’t move after the Julian day 213, the velocity in this grid is not zero, I want to know why, thank you very much.

Which version of EE and what release date are you using?