无法从我的Go服务器上“保存”传入的Cookie

Question

I made a go server that can do the basics. Now I want to do a request to my server from my node.js frontend (Axios) get a cookie back (for my login system) here is the code for putting the cookie in my response:

var hashKey = []byte("testkey") //for testing purpopes
var blockKey = []byte(securecookie.GenerateRandomKey(32))

var s = securecookie.New(hashKey, blockKey)
  if encoded, err := s.Encode("cookie-name", value); err == nil {
    cookie := &http.Cookie{
      Name:     "cookie-name",
      Value:    encoded,
      Path:     "/",
      Secure:   true,
      HttpOnly: true,
    }

    http.SetCookie(*w, cookie) // w = *http.ResponseWriter

...

when I use my REST tool to see what I get I can see that the 'set-cookie' header is present. The same is If I inspect in Microsoft Edge I can see the set-cookie header. But if I inspect in Google Chrome then I can't see the header. Also if I look in the cookies tab in both Chrome and edge the cookie is not set.

this is my function that is ran for the request:

async post( url, data, ct ) {
    try {
        const res = await axios.post(url, data, {
            headers: {
                'Content-Type': (ct || "text/plain")
            },
            withCredentials: true
        });
        if (res.status === 200) {
    return res.data;
        }
    } catch (e) {
        console.error(e);
        return false;
    }
}

my Response Headers:

server: nginx/1.14.0 (Ubuntu)
date: Thu, 17 Jan 2019 14:29:07 GMT
content-type: text/plain charset=utf-8
content-length: 4
connection: keep-alive
setcookie:cookiename=MTU0NzczNTM0N3xGOTJYUUw5TFNXZHI2dU9jT3hCeTZUTE5TaTBFNU1XN1F 5WGMzb3c1dGZRUENEU2xPZHFwTXJQLW8zND18_VCYxNVRbIAUrs9_8EcGpTUEiqVyYL_2M5Olbjhnkeg =; Path=/
access-control-allow-origin:https://beta.bvwitteveen.nl
access-control-allow-methods:GET, POST, OPTIONS
access-control-allow-credentials:true
access-control-allow-headers:DNT,User-Agent,X-Requested-With,If- 
ModifiedSince,Cache-Control,Content-Type,Range,Set-Cookie
access-control-expose-headers:Content-Length,Content-Range

Why is my cookie behaving so weird? What am I doing wrong here?