Why are injecton simulation results different for similar parts?

Hi,

I made an injection simulation in SW Plastics and I got strange results shown on the screenshots. It's clearly visible, that there are no shear stresses in 3 parts and velocity vectors at end of fill are pointing in random directions, but the parts are filling anyway.  Can it be some inaccurate model of runners?

SolidworksPlastics And Mold Design