After increasing QChart left margin, the previous area where the Y axis was isn't repainted

/*
 * peerPlotAreaChanged()
 * 
 * https://forum.qt.io/topic/109997/i-had-an-incredible-hard-time-to-align-horizontally-3-charts-qt-5-13-2
 */
void LinkedChart::peerPlotAreaChanged(const QRectF &pa)
{
    if (!plotArea().isNull()) {
        QMargins curMargins = margins();
        qDebug() << name() << curMargins << pa << plotArea();
        curMargins.setLeft(curMargins.left()+pa.left()-plotArea().left());
        setMargins(curMargins);
    }
}