Image Spacing Bug: Spacing is not match with input nrrd file

Dear Experts,
From input file the spacing is:
space directions: (0.98705792427062977,0,0) (0,0.98727250099182129,0) (0,0,1)

but after read input paraview, this spacing is: (1.0, 1.0, 1.0) which can be confirmed by information panel or see the exact number when debug inside program

Also from the code, i can only see the spacing is read from file but only set to outInfo, but not output image object:
outInfo->Set(vtkDataObject::SPACING(), this->DataSpacing, 3);

my paraview version is 5.9.0

Thanks in advance for your kind help!