Image.network rotates image

I have the problem, that Image.network shows an Image rotated in the webapp. But if I open the same url in a browser, the orientation is correct.

In my webap

In the browser

Can somebody help me?

My Code:

import 'package:flutter/material.dart';
import 'package:firebase/firebase.dart' as fb;
import 'dart:js' as js;

class NetworkImageError extends StatefulWidget {
  @override
  _NetworkImageErrorState createState() => _NetworkImageErrorState();
}

class _NetworkImageErrorState extends State<NetworkImageError> {
  String DownloadUrl='https://upload.wikimedia.org/wikipedia/commons/a/ad/Placeholder_no_text.svg'; //Placeholder

  GetURL()async{
    var _DownloadURL = await fb
        .storage()
        .refFromURL('gs://myBucket')
        .child('Pb_0000.png')
        .getDownloadURL();
    setState(() {
      DownloadUrl=_DownloadURL.toString();
    });
  }

  @override
  void initState(){
    GetURL();
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Container(
      child: Center(
        child: GestureDetector(
            onTap: (){
              js.context.callMethod("open", [DownloadUrl]);
            },
            child: Image.network(DownloadUrl)),
      ),
    );
  }
}