ECO-DF with an orthorhombic structrure

I am trying to capture the grain boundary motion of Forsterite(Mg2SiO4) using the ECO-DF. I constructed a bycrystal crystal structure which 32.7 malorientation angle. I followed the instruction from the LAMMPS page about fix orient/eco (fix orient/eco command — LAMMPS documentation) to write the orientationfile. I see the two different ids (-1 and 1) assigned to each grain seperately. So, I see the blue and red grain at 0 timestep. However, the motion of the grain boundary when visualized by the id numbers does not match with the motion of the actual grain boundary. For instance, it looks like the grain with grain id 1, red grain, shrinks. But, the grain boundary does not move when visualized without the grain id. If this makes sense.
I wanted to attach the visualizations to make it more sense along with my input file but I was not able to do it as a new user. If you could email me, [email protected], I will send them the files I used for simulations.
I am wondering if the fix orient/eco is not suitable for a orthorhombic structure.