Curious what cause this banding during slicing?

I’m in the middle of reprinting a lower that I had to adjust some setting on. But I noticed this banding on the old lower and the new one in printing currently.

I’m just wondering what would cause the this in the g code? I have fuzzy skin on so it was odd that there is a perfectly smooth band the wraps all the way around the grip and in the trigger area.

There is also another smooth band about 50 layers from the top rails as well ( not pictured) I’m just curious on what could cause this in the slicer. The bands are about 15-20 lays in height.