When QMainWindow is displayed in fullscreen, extra pixels will be displayed on another screen

import sys

from PySide6.QtCore import Qt
from PySide6.QtGui import QGuiApplication, QKeyEvent
from PySide6.QtWidgets import QApplication, QMainWindow

class mainwindow(QMainWindow):
    def __init__(self, screen_num: int = 0, parent=None):
        super().__init__(parent)
        self.screen = QGuiApplication.screens()[screen_num]
        self.setGeometry(self.screen.geometry())

    def keyPressEvent(self, event: QKeyEvent):
        if event.modifiers() == Qt.ControlModifier:
            if event.key() == Qt.Key_Q:
                self.close()


if __name__ == '__main__':
    app = QApplication(sys.argv)
    ui = mainwindow(screen_num=0)
    ui.showFullScreen()
    sys.exit(app.exec())

>>>print(self.screen.geometry(), self.screen.devicePixelRatio())
PySide6.QtCore.QRect(0, 0, 1707, 1067) 1.5