Power changes when doing 3d Engrave on PG acrylic (banding)

Yes. For some reason the machine introduces artificial banding even in solid areas - the example here uses rectangular vector objects. It varies by lpi. This was also Proofgrade acrylic. Acrylic shows the problem more than natural materials.

You can see it in the deeper (PG 3D engrave) sections of this piece, for example: