Looks like dual stack any-address is broken here. Only IPv6 socket will bound
here
Index: core/libs/dplugins/webservices/o2/src/o2.cpp
--- core/libs/dplugins/webservices/o2/src/o2.cpp.orig
+++ core/libs/dplugins/webservices/o2/src/o2.cpp
@@ -204,7 +204,7 @@ void O2::link() {
         } else {
             // Start listening to authentication replies
             if (!replyServer()->isListening()) {
-                if (replyServer()->listen(QHostAddress::Any, localPort_)) {
+                if (replyServer()->listen(QHostAddress::AnyIPv4, localPort_)) {
                     qDebug() << "O2::link: Reply server listening on port" << localPort();
                 } else {
                     qWarning() << "O2::link: Reply server failed to start listening on port" << localPort();
