Multiple pinches, separated by 100s of ns are caused by having two plasma sheaths moving down the anode separately. this in turn is generally due to the capacitors not firing together. it is common but not desirable as it splits up the energy.
You can also have multiple plasmoids with the same pinch–pulses of x-rays and neutrons separated by only tends of ns. This is more complicated, but also probably due to too broad a sheath. We’ve seen this already with FF-1.
Best shots are single pinch and single plasmoid–this maximizes density and fusion yield.
