QwebEngineView doesn't show anything

Question

I have created a piece of code that show a simple webpage (a bokeh graph saved in an html file). This code is working in Windows 10 at work, but on macos-mojave, using PyQT5.9, with Python 3.6, the opened window don't show anything, and makes python crash.

Could anyone helps ? Many thanks

import sys
from PyQt5.QtWidgets import (QApplication)
from PyQt5.QtWebEngineWidgets import QWebEngineView
from PyQt5 import QtCore

class Principale():
    def __init__(self):
        self.view = QWebEngineView()
        self.view.load(QtCore.QUrl("/Users/moncompte/Desktop/essai.html"))
        self.view.show()


# Create a custom font
# ---------------------


app = QApplication(sys.argv)
fenetre=Principale()
sys.exit(app.exec_())