[Material Style] TextArea + ScrollView produce drawing issue

import QtQuick 2.12
import QtQuick.Controls 2.5
import QtQuick.Window 2.12

Window {
    visible: true
    width: 640
    height: 480
    title: qsTr("Hello World")

    ScrollView {
        anchors.centerIn: parent

        contentWidth: control.implicitWidth
        contentHeight: control.implicitHeight

        TextArea {
            id: control
            text: "Text goes here."
        }
    }
}

TextArea {
    background: null
}