WebView fails to load OAuth Pages with Qt5.9.3

Using WebView to handle OAuth does not work with Qt 5.9.3. This is a regression as this was previously working with Qt5.9.2.

Our machine is running Red Hat Enterprise 7.0 using OpenSSL version 1.0.1e.
However, we were not able to reproduce this problem using Ubuntu 16.04 with OpenSSL version 1.0.0. Here is an example:

import QtQuick 2.6
import QtQuick.Controls 1.4
import QtWebView 1.1

ApplicationWindow {
    id: appWindow
    width: 800
    height: 600

    WebView {
        anchors.fill: parent
        url: "https://www.arcgis.com/sharing/rest/oauth2/authorize"
    }
}

The following gets outputted to the console:

[10538:10549:1212/115939.396034:ERROR:cert_verify_proc_openssl.cc(212)] X509 Verification error unable to get local issuer certificate : 20 : 1 : 4

We have also attached a screenshot of what appears in the WebView