Does Appian Integration Convert Document to BASE64 String If the document field is under nested cdt?

Hi 

I need to pass document as a base64 string to third party integration and the structure is as a nested cdt. I did configure everything correct in cdt and passed cdt as a integration body. But I'm getting a timeout error. 

Could anyone faced similar issue?

When I did check on request, Appian is converting into xml code, and it's adding <n> to the xml. For example <n1: OlUploadDocument></n1: OlUploadDocument> But it should convert as <OlUploadDocument></OlUploadDocument> and when I remove this <n> and sending it as a body in postman it's working. I was thinking is it because of extra <n> in the structure? May I know, how to overcome?

Please let me know

Thanks