wrapping it in vbox did not help 😞 here's roughly what I'm doing:

override val root = borderpane {
        top {
            hbox {
// stuff
            }
        }
        center {
            vbox {
                stackpane {
                    imageview(controller.image) {
                        isPreserveRatio = true
                        fitHeightProperty().bind((parent.parent as Pane).heightProperty())
                        fitWidthProperty().bind((parent.parent as Pane).widthProperty())
                    }
                }
            }
        }
    }