make_rest_request seems to corrupt docx file when sent with apex_web_service.append_to_multipart se

When I make a multipart (form) rest request and I send a .docx document the rest server doesn't recognize it. It said unrecognizable mediatype. When i send it with postman it works fine.

Code:

procedure add_new_document(p_id in documents.id%type) is

  

  cursor c_documents(b_id swf_documenten.id%type) is

   select *

   from  documents

   where id = b_id;

  

 /*

 TABlE DOCUMENTS

 *ID              NUMBER        No

  FORMAAT            VARCHAR2(100 CHAR)  Yes       Content-type / mimetype

  DOCUMENTHASH         VARCHAR2(255 CHAR)  Yes

  FILENAME           VARCHAR2(255 CHAR)  Yes

  DOCUMENT           BLOB         Yes

 */

  

  l_url   varchar2(4000 char);

  l_document documents%rowtype;

  

  l_multipart  apex_web_service.t_multipart_parts;