MPI-related grid function loading issue

Dear NGSolve developers,

I recently updated NGSolve to git revision baa43 and found that my older code
for loading a grid function from NGSolve’s binary format doesn’t work anymore.
Below is a minimal working example (the code files and binary function are attached):

from ngsolve import *                                                                                                                                     
import netgen.meshing                                                                                                                                            
from netgen.geom2d import unit_square                                                                                                                                                                                                                               

# setup the mesh                                                                                                                                                                           
if mpi_world.rank == 0:                                                                                                                                                                    
    ngmesh = Mesh("mesh_subsquare.vol").ngmesh                                                                                                                                           
    ngmesh.Distribute(mpi_world)                                                                                                                                                     
else:                                                                                                                                                                                       
    ngmesh = netgen.meshing.Mesh.Receive(mpi_world)                                                                                                                                      
    ngmesh.SetGeometry(unit_square)                                                                                                                                                     
                                                                                                                                                                                           
mesh = Mesh(ngmesh)                                                                                                                                                                     
                                      
# load function                                
gf = GridFunction(H1(mesh, order = 4))                                                                                                                                                
gf.Load("ushape_smooth.ngs", parallel = True) 
                                                                                                                                          
VTKOutput(ma = mesh, coefs = [gf], names = ["ushape"], filename="ushape_" + str(mpi_world.rank)).Do()                                                                                                                                                                           

At git revision 6f862 the vtk files show the right function (a phase field with the shape of a u,
somehow I cannot get the corresponding image attached).
At baa43, however, the result is


In non-MPI mode everything is still fine.
I couldn’t find a hint in the documentation. Am I using something wrong?

All the best,
Philipp

Attachment: mwe.tar_2020-09-20-3.zip

works again with the latest nightly …
Joachim

Thanks a lot!

Best,
Philipp