Negative axial stock to leave creates second pass

[BbellYS6XC]

In the attached file, I have a single setup and single toolpath, a 3D Pocket. Whenever axial stock-to-leave is 0 or greater, it works just fine.

If I set the axial stock-to-leave at -0.01 (I want it to cut 0.01 below the bottom of the model), it does this crazy first pass at 0.01 depth that doesn't respect the radial stock to leave. Then it goes on to do the desired cut.

The desired behavior is that it clears the pocket at full depth, leaving 0.05 on the sides and cutting 0.01 deeper than the model.

Why is this happening? What do I need to do to get it to do what I want?

Thanks

[BbellYS6XC]

Huh. Apparently, there is a problem with the stock solid generated by the nesting add-in. After trying everything else and spending most of a day on this, I changed the setup's stock from "From solid" to "Relative Size Box" and the problem went away.