ts.get_particle( ['id'], species='beam') returns 0

[ppiot]

All,
I am trying to follow particle given their ID but notice when loading the particle in openPMD all the IDs are set to zero; see screenshot below for my openPMD output. The simulation were performed with WARP where I save the particle as follows:

diag2 = ParticleDiagnostic( period=diag_period, top=top, w3d=w3d,
        species={species.name : species for species in listofallspecies},
        particle_data=["position","momentum","weighting","id"],
        comm_world=comm_world, lparallel_output=parallel_output,
        write_dir=diag_dir  )
installafterstep( diag2.write )

The other quantities (e.g. momentum and positions) are all working properly and can be read in openPMD.

Thank you,  -- Philippe.