Pyside 6.5.1 widget created in for-loop has wrong attributes

Question

I am using pyside6 in the current version 6.5.1. I encounter the following problem which I did not have in version 6.4.2. The buttons displayed in the main window are assigned object names, which are to be printed by clicking. However, all buttons always print "row=0, col=0" after click. The same happens with other widget attributes.

from PySide6.QtWidgets import QPushButton, QWidget, QMainWindow, QGridLayout, QApplication


class CustomButton(QPushButton):
    def __init__(self, parent: QWidget, row: int, col: int, slot: Callable):
        super().__init__(parent=parent)
        self.setObjectName(f'{row=}, {col=}')
        self.setText(f'{row=}, {col=}')
        self.released.connect(lambda: slot(self))


class MainWindow(QMainWindow):
    def __init__(self, parent: QApplication):
        super().__init__()

        self.central_widget = QWidget()
        self.setCentralWidget(self.central_widget)
        self.layout = QGridLayout(self.central_widget)
        self.create_buttons()

    def create_buttons(self):
        for r in range(10):
            for c in range(10):
                button = CustomButton(self, r, c, self.button_clicked)
                self.layout.addWidget(button, r, c)

    def button_clicked(self, button: QPushButton):
        print(button.objectName())


if __name__ == '__main__':
    app = QApplication()
    window = MainWindow(app)
    window.show()
    app.exec()

With version 6.4.2, however, the correct object names are printed. What could be the reason for this?