QObject::connect(QObject, Unknown): invalid nullptr parameter on app startup

I have application like this

int main(int argc, char *argv[])
{ 
QNetworkAccessManager qnam;
return 0;
}

And I get this on std output

qt.core.qobject.connect: QObject::connect(QObject, Unknown): invalid nullptr parameter
qt.core.qobject.connect: QObject::connect(QObject, Unknown): invalid nullptr parameter

All fine in 6.2.4