Aligned SPHARM models flip inside out during PCA

Operating system: Windows
Slicer version: 4.0.1
After following through with the shape population analysis module, the resultant PCA output has the models turning inside out. Since the three SPHARM.vtk files that make up the PCA have no obvious issues why does this happen?? For reference, the included screenshots show the inside out problem; attached as well are the models that had been aligned prior to shape pop. analysis and uploaded to slicerSALT

SPHARM.vtk files