QNetworkSettingsIPv6 does not work at all

With a network card connected to the network QNetworkSettingsIPv6 getters report garbage:

This

qDebug() << "ipv6 method: " << m_eth[id]->ipv6()->method();
qDebug() << "ipv6 address: " << m_eth[id]->ipv6()->address();
qDebug() << "ipv6 gateway: " << m_eth[id]->ipv6()->gateway();
qDebug() << "ipv6 prefix length: " << m_eth[id]->ipv6()->prefixLength();
qDebug() << "ipv6 privacy: " << m_eth[id]->ipv6()->privacy();

Outputs 

ipv6 method: -1285257979
ipv6 address: ""
ipv6 gateway: ""
ipv6 prefix length: 0
ipv6 privacy: -1285275707

where m_eth[id] is a valid service because I'm able to change ipv4 properties.

method and privacy numbers change as I connect/disconnect the network cable. address, gateway are always empty and the prefix length always 0.

The QNetworkSettingsService::ipv6Changed signal is never triggered, after I change the QNetworkSettingsIPv6 properties and I call QNetworkSettingsService::setupIpv6Config.

QNetworkSettingsService::ipv6Changed is only triggered when I change the ipv6 property from terminal with connmanctl config. The member value are still not reported properly.

ipv6 addresses are reported for the interfaces with ifconfig

So in the current form QNetworkSettingsIPv6 is completely broken.