title: Rectangle is not shown in QML
body: <p>In this <code>QML</code> example the <code>Rectangle</code> is NOT shown. The label <em>Usuarios</em> does appear, but the rectangle itself does not. Very weird behavior , can you tell why is that? You can test this example with <code>qmlscene</code>.</p>
  
  <p>Example code:</p>
  
  <p>Main file:</p>
  
  <pre><code>$ cat UsersGroups.qml 
  import QtQuick 2.7
  import QtQuick.Controls 2.0
  import QtQuick.Layouts 1.3
  
  Page {
      anchors.fill: parent
      header: TabBar {
          id: bar
          width: parent.width
          TabButton {
              text: qsTr("Users")
          }
          TabButton {
              text: qsTr("Groups")
          }
          TabButton {
              text: qsTr("Schedules")
          }
      }
      StackLayout {
          width: parent.width
          currentIndex: bar.currentIndex
          Users {
              id: users
          }
          Groups {
              id: groups
          }
          Schedules {
              id: schedules
          }
      }
  }
  </code></pre>
  
  <p><strong>Secondary files</strong></p>
  
  <p>Users file:</p>
  
  <pre><code>$ cat Users.qml 
  import QtQuick 2.7
  import QtQuick.Controls 2.0
  import QtQuick.Controls.Material 2.0
  import QtQuick.Dialogs 1.2
  import QtQuick.Layouts 1.3
  import Qt.labs.settings 1.0
  
  Item {
      anchors.fill: parent
      Rectangle {
          anchors.fill: parent
          color: "blue"
          border.color: "red"
          border.width: 5
          Label {
              text: "Usuarios"
          }
      }
  }
  </code></pre>
  
  <p>Groups file:</p>
  
  <pre><code>$ cat Groups.qml 
  import QtQuick 2.7
  import QtQuick.Controls 2.0
  
  Item {
      Label {
          text: "Grupos"
      }
  }
  </code></pre>
  
  <p>Schedules file:</p>
  
  <pre><code>$ cat Schedules.qml 
  import QtQuick 2.7
  import QtQuick.Controls 2.0
  
  
  Item {
      Label {
          text: "Schedules"
      }
  }
  </code></pre>
  
  <p>Will appreciate any pointers on solving this issue. </p>