@PelleKrogstad
I too had the same requirement. Looking further into I found out that the slot for onIgnoreSslErrors was never called as it is required for Self Signed Certificates and which cause these SSL errors.
So actually the request needs to modified a bit which could be done by re-implementing createRequest
Thus in QNAM subclassed class:

QNetworkReply *MyNam::createRequest(QNetworkAccessManager::Operation op, const QNetworkRequest &request, QIODevice *outgoingData) { QNetworkRequest req = request; QSslConfiguration conf = req.sslConfiguration(); conf.setProtocol(QSsl::AnyProtocol); req.setSslConfiguration(conf); QNetworkReply *reply = QNetworkAccessManager::createRequest(op, req, outgoingData); qDebug() << req.url(); return reply; }

And thus the ignoreSSLErrors slot was called where the errors were ignored. This worked for me. Let me know if it works for you.

Try to install the latest OpenSSL libraries for Windows. You can find it here : https://www.openssl.org/related/binaries.html