QStandartItem in QTreeView overlaps

from PySide6.QtWidgets import QApplication, QMainWindow, QStyledItemDelegate, QStyle, QStyleOptionViewItem, QTreeView
from PySide6.QtCore import QModelIndex
from PySide6.QtGui import QBrush, QStandardItem, QStandardItemModel, QPainter, QPainterPath, QPen, QFont

import sys

DISPLAY_ROLE = 0
BACKGROUND_ROLE = 8

class StyledItemDelegate(QStyledItemDelegate):
    def paint(self, painter: QPainter, option: QStyleOptionViewItem, index: QModelIndex):
        # painter.setRenderHint(QPainter.Antialiasing)

        path = QPainterPath()

        path.addRoundedRect(option.rect, 5, 5) 

        painter.fillPath(path, index.data(BACKGROUND_ROLE))

        painter.setPen(QPen(QBrush("black"), 2))

        painter.setFont(QFont("Segoe UI", 9, QFont.Normal))

        rect = option.rect
        rect.setX(rect.x() + 5)
    
        painter.drawText(rect, index.data(DISPLAY_ROLE))

        painter.setPen(QPen(QBrush("black"), 1))
        if QStyle.State_HasFocus & option.state:
            painter.drawPath(path)

class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()

        treeview = QTreeView()
        self.setCentralWidget(treeview)

        model = QStandardItemModel()
        treeview.setModel(model)
        treeview.setItemDelegate(StyledItemDelegate())
        treeview.header().setVisible(False)

        _ = QStandardItem("my item")
        model.appendRow(_)
        model.setData(_.index(), QBrush("#ffffff"), role=BACKGROUND_ROLE)

        _ = QStandardItem("my item")
        model.appendRow(_)
        model.setData(_.index(), QBrush("#ffffff"), role=BACKGROUND_ROLE)

app = QApplication(sys.argv)

window = MainWindow()
window.show()

sys.exit(app.exec())