PySide6 QLineSeries doesn't plot correctly

def initChart(self):
        self.axis_x = QValueAxis()
        self.axis_x.setTitleText("x")

        self.axis_y = QValueAxis()
        self.axis_y.setTitleText("y")

        self.series = QLineSeries()
        self.series.setName("Line Series")

        self.series.append(0, 6)
        self.series.append(1, 4)
        self.series.append(2, 5)

        self.series.attachAxis(self.axis_x)
        self.series.attachAxis(self.axis_y)

        self.axis_x.setRange(0, 2)
        self.axis_x.setTickCount(3)
        self.axis_y.setRange(0, 6)
        self.axis_y.setTickCount(7)

        self.chart = QChart()
        self.chart.setAnimationOptions(QChart.AllAnimations)
        self.chart.addAxis(self.axis_x, Qt.AlignBottom)
        self.chart.addAxis(self.axis_y, Qt.AlignLeft)
        self.chart.addSeries(self.series)

        self.ui.chartView.setChart(self.chart)
        self.ui.chartView.setRenderHint(QPainter.Antialiasing)