JV3 160s gray coming though with magenta stripes?

what's your nozzle test look like?
could be ink starvation or encoder strip/sensor issues buuuuuut those head strikes would lead me to believe that your material is tunneling through the printer in those areas, and the ink is not being fired straight-down as designed.

 

I don't know Mimakis, but it looks like your vinyl is tunneling in the print zone. A couple of places are high enough to get head strikes. This is throwing off your bi-directional and horizontal calibrations so ink isn't going where it needs to. Try decreasing print temps if you can.

Good luck