PyQt5 - Ubuntu 18.04 - Error 99 on QNetworkReply when request to HTTPS url

I'm building an app using Python 3.6 and PyQt5. I was on Ubuntu 16.04 I used to make HTTP request using QNetworkReply and QNetworkRequest from QtNetwork like so :

@pyqtSlot('QNetworkReply*')
def receiveReply(self, reply):
    buffer = reply.readAll()
    if (reply.error() != QNetworkReply.NoError):
        print("API - Error  " + str(reply.error()) + " : " + buffer.data().decode('utf8'))
        self.networkManager.clearAccessCache()
    else:
        print('yeah !')
    reply.deleteLater()

@pyqtSlot()
def sendRequest(self):
        request = QNetworkRequest(QUrl("https://www.google.fr"))
        self.networkManager.get(request)

(I'm showing a simplified version of my code that still throw the error)
Since I upgraded my OS to Ubuntu 18.04 I'm getting an error 99 (QNetworkReply::UnknownNetworkError) from the QNetworkReply everytime I'm making a request to a HTTPS url.
But if, in the example, I replace https://www.google.fr by http://www.google.fr it works perfectly. I'm guessing it has to deal with HTTPS url in general but I can't find why it's happening on Ubuntu 18. Thanks in advance if someone can help me !

Thanks to eyllanesc, here is the solution :

pip3 uninstall pyqt5
sudo apt-get install python3-pyqt5