Tizen Download API下载媒体文件异常问题求助

各位好，我最近在尝试用Tizen的Download API从服务器下载图片、视频、GIF等媒体文件，但遇到了一个棘手的问题：下载流程明明显示完成，文件也确实存到了指定路径，但打开后发现文件根本不是正常的媒体格式（比如这次测试的图片，完全无法正常打开）。不过用浏览器或者Postman访问同一个URL，却能正常获取到完整且格式正确的文件。

我是参照Tizen官方文档写的代码，具体代码如下：

const downloadUrl = 'https://magic-sign.cloud/v4/web/MSlibrary/wi-night-partly-cloudy.jpg';
const downloadFileName = 'wi-night-partly-cloudy.jpg';

var downloadRequest = new tizen.DownloadRequest(downloadUrl, path, downloadFileName, 'ALL', {'Content-Type' : 'image/jpeg'});

tizen.systeminfo.getPropertyValue('NETWORK', function(networkInfo) {
  if (networkInfo.networkType === 'NONE') {
    console.log(`Network connection is not available.
Download is not possible.`);
    downloadRequest = null;
  }
});

var listener = {
  /* When the download progresses (interval is platform-dependent) */
  onprogress: function(id, receivedSize, totalSize) {
    console.log('Received with id: ' + id + ', ' + receivedSize + '/' + totalSize);
  },
  /* When the user pauses the download */
  onpaused: function(id) {
    console.log('Paused with id: ' + id);
  },
  /* When the user cancels the download */
  oncanceled: function(id) {
    console.log('Canceled with id: ' + id);
  },
  /* When the download is completed */
  oncompleted: function(id, fullPath) {
    console.log('Completed with id: ' + id + ', full path: ' + fullPath);
  },
  /* When the download fails */
  onfailed: function(id, error) {
    console.log('Failed with id: ' + id + ', error name: ' + error.name);
  }
};

let downloadId = tizen.download.start(downloadRequest, listener);

tizen.download.getState(downloadId);
var state = tizen.download.getState(downloadId);
console.log(state);

var downloadRequest = tizen.download.getDownloadRequest(downloadId);
console.log(downloadRequest);

var MIMEType = tizen.download.getMIMEType(downloadId);
console.log(MIMEType);

调试过程中我发现几个异常的地方：

• 调用tizen.download.start()之前打印downloadRequest，结果和预期有差异（附截图）
• 启动下载后，再次获取downloadRequest和MIME类型，明明我在初始化时显式设置了Content-Type: image/jpeg，但获取到的MIME类型却不符合预期（附截图）
• 下载完成后，文件大小和浏览器下载的不一致，打开后是损坏的状态（附截图）

有没有哪位前辈遇到过类似的问题？求指点一下可能的原因或者排查方向，谢谢！

备注：内容来源于stack exchange，提问作者Mohamed Raddaoui