Cannot get inner nodes of XML response using AFNetworking Objective-C

I'm making POST Request from my iOS application and its getting back the Response but excluded from it some nodes. I've tried the same POST Request and from Wizdler (Chrome Extension) and the full response is received correctly without any missing nodes. I'm using AFNetworking Library to make the http post request.

The "country" node is retrieved in the iOS request but it's retrieved normally in requests from other tools. What could make such a problem ?

I've discovered that changing the header of my http request of Content-Type="text/xml" to "text/plain" solves the problem. But I'm still looking for justification of why this may have solved the issue.