combo box list keeps snapping to top

[kgregory]

I have a fairly generic combo box that I use across my application. Nothing fancy, just a simple combo box that is stylized for my app's aesthetics.

My problem is that in one instance of this combo box, there are now two many selection options to fit on the screen. When I try to scroll to the bottom of the list, it always snaps back to the first item, making it impossible to see part of the list. Can anyone tell me why it's like this or how to get it to allow me to scroll to the bottom?

import QtQuick
import QtQuick.Controls

ComboBox{
    id: myComboBox
    property real cornerRadii: 30
    font.family: "Helvetica"

    delegate: ItemDelegate {
            width: myComboBox.width
            contentItem: Text {
                text: modelData
                color: parent.highlighted ? "#000000" : "#FFFFFF"
                font: myComboBox.font
                elide: Text.ElideRight
                horizontalAlignment: Text.AlignLeft
                verticalAlignment: Text.AlignVCenter
            }
            background: Rectangle {
                //implicitWidth: parent.width
                //implicitHeight: parent.height
                //visible: myComboBox.down || myComboBox.highlighted || myComboBox.visualFocus
                color: parent.highlighted ? "#FFFFFF" : "#00000000"
                border.color: parent.highlighted ? "#00000000" : "#FFFFFF"
                border.width: 1
                radius: myComboBox.cornerRadii
            }
            highlighted: myComboBox.highlightedIndex === index
        }
    background: Rectangle {
            width: parent.width
            height: parent.height
            color: "#D0000000"
            border.color: "#FFFFFF"
            border.width: 1
            radius: myComboBox.cornerRadii
        }
    contentItem: Text {
            leftPadding: .01*parent.width
            rightPadding: parent.indicator.width + parent.spacing

            text: parent.displayText
            font: parent.font
            color: parent.pressed ? "#C0C0C0" : "#FFFFFF"
            horizontalAlignment: Text.AlignLeft
            verticalAlignment: Text.AlignVCenter
            elide: Text.ElideNone
        }
    popup: Popup {
            y: parent.height - 1
            width: parent.width
            implicitHeight: contentItem.implicitHeight
            padding: 1
            font: parent.font //delete this?
            
            contentItem: ListView {
                clip: true
                implicitHeight: contentHeight
                model: myComboBox.popup.visible ? myComboBox.delegateModel : null
                currentIndex: myComboBox.highlightedIndex
                ScrollIndicator.vertical: ScrollIndicator { }
            }

            background: Rectangle {
                border.color: "#FFFFFF"
                color: "#D0000000"
                radius: myComboBox.cornerRadii
            }
        }
}