The XML tab in the Inspector is empty for the following request.

POST http://vodafone.station/data_model.cgi HTTP/1.1
Host: vodafone.station
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:48.0) Gecko/20100101 Firefox/48.0
Accept: application/xml, text/xml, */*; q=0.01
Accept-Language: it-IT,it;q=0.8,en-US;q=0.5,en;q=0.3
Accept-Encoding: gzip, deflate
Content-Type: text/xml; charset="utf-8"
Method: POST
SOAPServer:
SOAPAction: cwmp:SetParameterValues
X-Requested-With: XMLHttpRequest
Referer: http://vodafone.station/main.cgi?page=wifi_adv.html
Content-Length: 579
Cookie: wbm_cookie_session_id=0BEA95D47976B447
DNT: 1
Connection: keep-alive
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"><soapenv:Header><DMCookie>993650944</DMCookie></soapenv:Header><soapenv:Body><cwmp:SetParameterValues xmlns=""><ParameterList><ParameterValueStruct><Name>InternetGatewayDevice.LANDevice.5.WLANConfiguration.9.X_JUNGO_COM_Standard</Name><Value>g</Value></ParameterValueStruct><ParameterValueStruct><Name>InternetGatewayDevice.LANDevice.5.WLANConfiguration.9.X_JUNGO_COM_LowerSideBand</Name><Value>0</Value></ParameterValueStruct></ParameterList></cwmp:SetParameterValues></soapenv:Body></soapenv:Envelope>