Maybe this is not the best help You cant get, but first: why don't qDebug() << incomingdata; ? Dump the data in each reply and see for Yourself what's going on.
Alternatively, if you don't want rewrite/write code, use sniffing tool, i.e. Wireshark, don't download anything (that way less output in Wireshark hence nicer work) and run sniffer/Your program and see What Really is going on.