Reproduction

import QtQuick
import QtQuick.Window

Window {
    width: 640
    height: 480
    visible: true
    title: qsTr("Font Style Selection Broken")

    Text {
        text: "Arial Bold"
        anchors.centerIn: parent

        font {
            pixelSize: 72
            family: "Arial"
            styleName: "Bold"
        }
    }
}