Sounds to me like it might be a loose connection somewhere in the hot end circuit. I've had it happen a couple of times. Moving back and forth weakens connection points, and it gets exacerbated when it is moving in short fast bursts that shake the whole machine.
The first time this happened to me, it seemed random, but then I realized it was always near the same spot on the bed. I eventually traced it to a broken solder connection. Hopefully it's something that simple for you.
The first time this happened to me, it seemed random, but then I realized it was always near the same spot on the bed. I eventually traced it to a broken solder connection. Hopefully it's something that simple for you.