MapPolygon border color doesnt change on update

[steve.desa]

Hi, I'm working on a project in Qt V5.12. I have a mapviewitem that is supposed to plot mappolygons on update of the model supplied to it. all of my attributes (color, path) change on model update except for border color. why is this the case? can somebody help me with a fix. Thanks

MapItemView {
                model: mapPolygonsList
                delegate: MapPolygon {
                    id: mapPolygonPlot
                    path: model.points.map(v => QtPositioning.coordinate(v.latitude, v.longitude))
                    border.color: model.borderColor
                    border.width: model.borderWidth
                    color: model.Color
                }
            }