Inconsistent rendering for bold variable fonts set via setWeight/setVariableAxis

from PySide6.QtWidgets import QApplication, QVBoxLayout, QWidget, QLabel
from PySide6.QtGui import QFont
import sys

def main():
    app = QApplication(sys.argv)
    window = QWidget()
    box = QVBoxLayout()
    
    label1= QLabel("setWeight: The quick brown fox jumps over the lazy dog")
    font1 = QFont("Cantarell", 12)
    font1.setWeight(QFont.Bold)
    label1.setFont(font1)
    
    label2 = QLabel("setVariableAxis: The quick brown fox jumps over the lazy dog")
    font2 = QFont("Cantarell", 12)
    font2.setVariableAxis(QFont.Tag("wght"), float(QFont.Bold))
    label2.setFont(font2)

    box.addWidget(label1)
    box.addWidget(label2)

    window.setLayout(box)
    window.show()

    sys.exit(app.exec())

if __name__ == "__main__":
    main()