Rear z-axis motor not running smoothly

So I finally got round to building my v-core 3 500, got the bltouch setup and ran my first home which worked.
I then ran z-tilt and the rear didn't rise up far enough.
I looked closer and saw that it wasn't running smoothly, it stopped and then started again.
I checked the electrical connections and it looks good.

Any ideas?
Was this page helpful?