Backlash corrects itself as it moves. A cutter will force a table one way and the machine will overcompensate if the setting is wrong. That will give stall marks. Or could be your program. Say for some reason the post that was output to your machine had several movements in a straight line could cause pause marks too.
Like
G1 X1Y-4
X1.5Y-4
X2.0Y-4
X2.5Y-4
and so on. Think it's called scaling.
Although it's a straight line, all the extra code causes pause.
If this machine is a "New" purchase, I'd be on the phone with who I bought the machine from, telling them to come fix their machine. Based on picture of swirls we'll also need pics of the cutting tool, and program. There is slop somewhere. Those are bounce or pause markings. Not familiar with machine brand or name. So depending on how ridged the machine could have bearing as well.
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