[bug]Error in function result of moving layer

Photoshop
1

When I use the “moveabove” and “movebelow” functions, I find that their results are the same. Is this a bug?

app.activeDocument.activeLayers[0].duplicate();

app.activeDocument.activeLayers[0].duplicate();

var DW=app.activeDocument.activeLayers[0];

app.activeDocument.activeLayers[0].name="DW"

app.activeDocument.activeLayers[0].duplicate();

app.activeDocument.activeLayers[0].duplicate();

app.activeDocument.activeLayers[0].duplicate();

var COPYL=app.activeDocument.activeLayers[0];

app.activeDocument.activeLayers[0].name="COPY"

COPYL.moveAbove(DW);

// COPYL.moveBelow(DW);