Question about GoBoxPort

If I’m using a GoBoxPort with my nodes and want links between nodes to leave from the bottom edge and enter from the top edge, is it just a matter of setting the ToSpot and FromSpot of the port?
this.Port.ToSpot = GoObject.TopCenter;
this.Port.FromSpot = GoObject.BottomCenter;
I tried this and it doesn’t seem to work, as I still get links entering and leaving on the side of my nodes (GoBoxNode).

That ought to work. Or at least it does for me.
If you don’t need the features of a GoBoxPort, where it tries to be smart about positioning the link connection points, you might as well use a regular GoPort. It would be easiest to just use a GoBasicNode with the .LabelSpot set to Middle and the .Shape set to a GoRectangle, along with the two statements you already tried:
GoBasicNode n = new GoBasicNode();
n.LabelSpot = GoObject.Middle;
n.Shape = new GoRectangle();
n.Port.ToSpot = GoObject.TopCenter;
n.Port.FromSpot = GoObject.BottomCenter;
n.Brush = …
n Text = …