Modal dialog with Material Style bug with Qt5.15.0

[Kobey]

When opening a dialog within a dialog and setting the second dialog as modal, and focusing any controller with a ToolTip it is possible to click controllers behind the modal overlay but only in the first dialog.

From what I've tested it is only an issue when using Material style.

import QtQuick 2.15
import QtQuick.Controls 2.15
import QtQuick.Layouts 1.15

ApplicationWindow {
    id: window
    visible: true
    width: 640
    height: 480
    title: "Modal Error"

    RowLayout {
        Button {
            text: "Open dialog"
            onClicked: mainDialog.open()
        }
        CheckBox {
            text: "Click me 1"
        }
    }

    Dialog {
        id: mainDialog
        x: 50
        y: 50
        height: parent.height - 100
        width: parent.width - 100
        closePolicy: Popup.NoAutoClose
        standardButtons: Dialog.Close

        RowLayout {
            anchors.fill: parent

            Button {
                text: "Open Dialog"
                onClicked: dialog.open()
            }
            Item {
                Layout.fillWidth: true
            }
            CheckBox {
                text: "Click me 2"
            }
        }

        Dialog {
            id: dialog
            title: "Dialog"
            modal: true
            closePolicy: Popup.CloseOnEscape
            height: parent.height - 100
            width: ( parent.width / 2 ) - 100
            x: 50
            y: 50

            TextField {
                id: textField
                placeholderText: "Focus me"
                anchors.centerIn: parent
                ToolTip.text: "ToolTip"
                ToolTip.visible: textField.activeFocus
            }
        }
    }
}

One workaround could be to set overlay to a pane to handle the mouse-click event. But I'm interested to find the root cause.

Dialog {
    id: dialog
    Overlay.modal: Pane { background: Item {} }
}