message: add  X.ExchangeFaceNbrData - deleted by mistake
diff: @@ -60,6 +60,7 @@ void ParNonlinearForm::Mult(const Vector &x, Vector &y) const
  aux1.HostReadWrite();
  X.MakeRef(aux1, 0); // aux1 contains P.x
  + X.ExchangeFaceNbrData();
  const int n_shared_faces = pmesh->GetNSharedFaces();
  for (int i = 0; i < n_shared_faces; i++)
  {
  