Node-fetch连接本地C# HttpListener服务器遇ECONNREFUSED错误

Linux环境下，通过浏览器访问本地9000端口的C# HttpListener服务器可正常返回200状态码，但将浏览器中使用的URL直接复制到node-fetch中调用时，却抛出ECONNREFUSED错误。

node-fetch调用代码 #

await fetch(`http://localhost:9000/renderAvatar.3d?pant=http://localhost/assets/2.png&face=http://localhost/assets/0.png&shirt=http://localhost/assets/1.png&name=de&trick=e`)

C#服务器核心代码 #

HttpListener httpServer;
public void SomeFunction() {
    //Some boilerplate for http server definitely not stolen amogus
    httpServer = new HttpListener();
    httpServer.Prefixes.Add("http://localhost:9000/");
    httpServer.Start();
    Task demo = Server();
    demo.GetAwaiter().GetResult();

}
public async Task server() {
    while(true) {
        HttpListenerContext ctx = await httpServer.GetContextAsync();
        HttpListenerRequest req = ctx.Request;
        HttpListenerResponse resp = ctx.Response;
        if(req.HttpMethod == "GET") {
            if(req.Url.AbsolutePath.ToString() == "/renderAvatar.3d") {
                var parameters = HttpUtility.ParseQueryString(req.Url.Query);
                if(parameters.Count > 3) {
                    var pant = parameters[0].ToString();
                    var face = parameters[1].ToString();
                    var shirt = parameters[2].ToString();
                    var name = parameters[3].ToString();
                    // 因属专有代码，无法提供更多内容

错误信息 #

FetchError: request to http://127.0.0.1:9000/renderAvatar.3d?pant=http://localhost/assets/2.png&face=http://localhost/assets/0.png&shirt=http://localhost/assets/1.png&name=de&trick=e failed, reason: connect ECONNREFUSED 127.0.0.1:9000
    at ClientRequest.<anonymous> (file:///home/(confidental)/backend/node_modules/node-fetch/src/index.js:108:11)
    at ClientRequest.emit (node:events:527:28)
    at Socket.socketErrorListener (node:_http_client:454:9)
    at Socket.emit (node:events:527:28)
    at emitErrorNT (node:internal/streams/destroy:157:8)
    at emitErrorCloseNT (node:internal/streams/destroy:122:3)
    at processTicksAndRejections (node:internal/process/task_queues:83:21) {
      type: 'system',
      errno: 'ECONNREFUSED',
      code: 'ECONNREFUSED',
      erroredSysCall: 'connect'
    }

当前临时解决方案是通过程序调用Chrome访问后关闭，但内存占用过高，寻求合理解决办法。（注：9000端口未被防火墙限制）

内容的提问来源于stack exchange，提问作者drk1