It appears to be tool related, poor cut quality, possible Dull Tool. Spacing between the outer cut and the inner cut is related to the settings you are using. It is doing exactly what you are asking it to do. It also appears your machine may not be holding tolerances very well try scaling down a thenth or so and see if that helps if your cutter is carbide try speeding it up. slow down feed speeds a bit, use new tool or sharp tool. Deflection of the tool or material could also be a factor.