URLLoader error #2032 with AIR 20 (AIR 19 works)

Hello, I've updated from Flex 4.14.0 + AIR 19 build 143 to Flex 4.14.0 + AIR 20 build 206, now my code with URLLoader on a HTTP connection without SSL doesn't work on iOS (error #2032).

The device I'm testing on is an iPad Mini Retina with iOS 9.2.

The url is reachable with Safari.

Snippet is the following:

var url:String = "http://www.falcosoft.it/catalogo/catalogo.xml";

var onComplete:Function = function(event:Event):void {

  // this code doesn't get called

  loader.removeEventListener(Event.COMPLETE, onComplete);

};

var onIOError:Function = function(event:IOErrorEvent):void {

  // the program always calls onIOError with error #2032: Stream error

  loader.removeEventListener(IOErrorEvent.IO_ERROR, onIOError);

};

var onSecurityError:Function = function(event:SecurityErrorEvent):void {

  loader.removeEventListener(SecurityErrorEvent.SECURITY_ERROR, onSecurityError);

};

var request:URLRequest = new URLRequest(url);

request.method = URLRequestMethod.GET;

var loader:URLLoader = new URLLoader();

loader.dataFormat = URLLoaderDataFormat.BINARY;

loader.addEventListener(Event.COMPLETE, onComplete);

loader.addEventListener(IOErrorEvent.IO_ERROR, onIOError);

loader.addEventListener(SecurityErrorEvent.SECURITY_ERROR, onSecurityError);

loader.load(request);