我有一个奇怪的问题。 在浏览器上放置请求时出现cors错误：

access to fetch at 'http://localhost:3015/pathtest/api/v1/results/cc7637578fad1a6fcfb4249fbf000a13/load' from origin 'https://localhost:9444' has been blocked by CORS policy: Method PUT is not allowed by access-Control-Allow-Methods in preflight response.

这是我的在后端（nodejs）中启用cors的代码。其他所有api请求均已通过以下代码修复，并且仅将put仍返回cors问题：

app.use(function(req,res,next) {
  // res.header("access-control-allow-origin","*");
  // res.header("access-Control-Allow-Headers","Origin,X-Requested-With,Content-Type,accept");
  // res.header('access-Control-Allow-Methods','PATCH,PUT,POST,GET,DELETE,OPTIONS');
  //     // allow preflight
  //     if (req.method === 'OPTIONS') {
  //       res.send(200);
  //   } else {
  //       next();
  //   }

  res.header('access-control-allow-origin','*');
res.header('access-Control-Allow-Methods','GET,PATCH,OPTIONS');
res.header('access-Control-Allow-Headers','Content-Type,Authorization,Content-Length,X-Requested-With');
// allow preflight
if (req.method === 'OPTIONS') {
    res.send(200);
} else {
    next();
}
});

我想念什么吗？

**更新