I'm having this same issue in my code, but I'm not passing addPostFile method. So I was wondering if I need to pass some others configuration to the request object.
Any idea?
Here is my code
$request = new HttpRequest($myURL, HttpRequest::METH_GET);
$request->setBody('');
$request->addQueryData(
array(
'service' => 'delete',
'data' => $dataSend
));
$request->send();