Possible bug related to domain decomposition

[Yin-YinjianZhao]

Recently, we are using WarpX to do some 2D simulations. We found that when numprocs = [4,16] is changed, the results look very different. For example, the three plots below used numprocs = [1,64], numprocs = [4,16], numprocs = [16,4], respectively. The mobility diagnostics are: numprocs = [1,64]: numprocs = [4,16]: numprocs = [16,4]:

I wonder if similar bugs have been detected before @RemiLehe @ax3l @dpgrote ? Note the cell sizes are:

nx = 96
nz = 256

We will try to use only multiples of 2 and test again different domain decompositions.