qml Markdown format not working as expected

import QtQuick 2.14
import QtQuick.Controls 2.14
import QtQuick.Window 2.14
import QtQuick.Layouts 1.14

Window {
    id: root
    visible: true
    width: 960
    height: 480

    QtObject {
    id: internals
    property string markdown_text: "*Italic* **Bold** ***Italic Bold***
# Heading 1
## Heading 2
[Link](http://a.com)
* List
* List
* List
- [x] @mentions, #refs, [links](), **formatting**, and <del>tags</del> supported
- [x] list syntax required (any unordered or ordered list supported)
- [x] this is a complete item
- [ ] this is an incomplete item

>quote, not working
Horizontal Rule not working
***
`Inline code` with backticks not working
```
# code block not working
print '3 backticks or'
print 'indent 4 spaces'
```
"
}
   RowLayout{
      anchors.fill: parent

      TextArea {
          id: te_output
          color: "black"
          Layout.fillWidth: true
          textFormat: TextEdit.MarkdownText
          text: internals.markdown_text
      }
      Text {
          id: t_output
          Layout.fillWidth: true
          textFormat: TextEdit.MarkdownText
          text: te_output.text
      }
   }
}