QML doesn't set the list model when adding tab dynamically the second time

[volcano]

I have a tab view and trying to add the same tab dynamically using a button.
However the second time, QML complains with "qrc:///main.qml:43: TypeError: Type error"

main.qml

import QtQuick 2.2
import QtQuick.Controls 1.1
import QtQuick.Layouts 1.1
 
ApplicationWindow {
    visible: true
    width: 640
    height: 480
    title: qsTr("Hello World")
    signal tabAdded(variant c)
 
    ListModel {
        id: toolbarModel
 
        ListElement {
            partColor: "red"
        }
        ListElement {
            partColor: "blue"
        }
    }
 
    ColumnLayout{
        anchors.fill: parent
 
        TabView{
            visible: true
            id:tabview
            Layout.fillHeight: true
            Layout.fillWidth: true
 
        }
        Button{
            text: "add tab"
            onClicked:{
 
                console.log("Component.onCompleted " + toolbarModel.get(0).name)
 
                var t = tabview.addTab("tab", Qt.createComponent("TabItem.qml"));
                console.log("Component.onCompleted b " + t)
                if(t != null)
                {
                    t.item.partsModel = toolbarModel
                    var last = tabview.count-1;
                    tabview.getTab(last).active = true; 
                    console.log(tabview.getTab(last).item);
                }
            }
        }
        Button{
            text: "remove tab"
            onClicked:{
 
                var last = tabview.count-1;
                tabview.getTab(last).active = false;
                console.log(tabview.getTab(last).item);
                tabview.removeTab(last)
            }
        }
    }
 
}

import QtQuick 2.2
import QtQuick.Controls 1.1
import QtQuick.Layouts 1.1

ApplicationWindow {
    visible: true
    width: 640
    height: 480
    title: qsTr("Hello World")
    signal tabAdded(variant c)

    ListModel {
        id: toolbarModel

        ListElement {
            partColor: "red"
        }
        ListElement {
            partColor: "blue"
        }
    }

    ColumnLayout{
        anchors.fill: parent

        TabView{
            visible: true
            id:tabview
            Layout.fillHeight: true
            Layout.fillWidth: true

        }
        Button{
            text: "add tab"
            onClicked:{

                console.log("Component.onCompleted " + toolbarModel.get(0).name)

                var t = tabview.addTab("tab", Qt.createComponent("TabItem.qml"));
                console.log("Component.onCompleted b " + t)
                if(t != null)
                {
                    t.item.partsModel = toolbarModel
                    var last = tabview.count-1;
                    tabview.getTab(last).active = true; 
                    console.log(tabview.getTab(last).item);
                }
            }
        }
        Button{
            text: "remove tab"
            onClicked:{

                var last = tabview.count-1;
                tabview.getTab(last).active = false;
                console.log(tabview.getTab(last).item);
                tabview.removeTab(last)
            }
        }
    }

}

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TabItem

import QtQuick 2.0
 
import QtQuick.Controls 1.1
 
Item{
    signal tabButtonClicked()
 
    property alias partsModel:parts.partList
 
    anchors.fill: parent
    Rectangle{
        id:colorRect
        height: 100
        width: 100
        z:23
        anchors.top : parent.top
        color: "red"
    }
 
    PartList{
        id : parts
        anchors.left:colorRect.right
        z:25
    }
}

import QtQuick 2.0

import QtQuick.Controls 1.1

Item{
    signal tabButtonClicked()

    property alias partsModel:parts.partList

    anchors.fill: parent
    Rectangle{
        id:colorRect
        height: 100
        width: 100
        z:23
        anchors.top : parent.top
        color: "red"
    }

    PartList{
        id : parts
        anchors.left:colorRect.right
        z:25
    }
}

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Partlist

import QtQuick 2.0
 
Item {
 
    property var partList
 
    ListView{
        model:partList
        height: 200
        width: 100
        delegate: delegateComp
    }
 
    Component{
        id: delegateComp
        Rectangle{
            id: rect
            height: 25
            width: 25
            color: partColor
 
            MouseArea{
                anchors.fill: parent
                onClicked: {
                    console.log("Color " + partColor)
                }
            }
        }
    }
}

import QtQuick 2.0

Item {

    property var partList

    ListView{
        model:partList
        height: 200
        width: 100
        delegate: delegateComp
    }

    Component{
        id: delegateComp
        Rectangle{
            id: rect
            height: 25
            width: 25
            color: partColor

            MouseArea{
                anchors.fill: parent
                onClicked: {
                    console.log("Color " + partColor)
                }
            }
        }
    }
}

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Kindly advice what step I'm missing