Neck Training Problem

I’ve recently started training my neck and I invested in a neck harness. I love the neck harness and feel it is more efficient than doing neck extensions and curls with a plate on my head because it deloads into my arms at the bottom of the neck curl but on the harness, it’s all in your neck. One problem I have is that the plate is shifting to one side of the chain and it feels much heavier on one side of my head than the other because the plate is shifted over just a little but it makes a big difference. Also, one side of my neck is always much more sore the neck day.
Anyone have any tips or recommendations?

Use a loading pin.