Cookies not saved in the browser

I am trying to set a cookie in my browser using a Python Flask backend however, when we call the set cookie function I am unable to observe the cookie being saved by the browser. The following is my current understanding about how this is supposed to work:

• Cookies are just key value pairs that may have an expiration which makes them persistent, otherwise they expire when the browser is closed
• to set a cookie, all that is necessary is to use the set-cookie header in the response. I call the flask response object’s set_cookie method to do this.
• the browser should automatically save the cookie and follow the expiration rules (the set_cookie header can be observed in the response received by the browser)

Making the request in Angular HttpClient

let headers = new Headers();
headers.append('Content-Type', 'application/json');
let options = new RequestOptions({ headers: headers, withCredentials: true });
const request_data = {'username': this.username, 'password': this.password};
this.http.post('http://localhost:8080/token', request_data, options)

Setting the cookie in Python Flask

g.response = make_response()
time = datetime.datetime.now() + datetime.timedelta(days=30)
g.response.set_cookie("auth_token", auth.token, expires=time)
return g.response

Plain text response in the browser

HTTP/1.1 200 OK
set-cookie: auth_token=7253f2fa43d7584741dcf8972dea8f; Expires=Fri, 05-Jan-2018 01:33:30 GMT; Path=/
vary: Origin
access-control-allow-credentials: true
access-control-allow-origin: http://127.0.0.1:4200
content-type: application/json
Expires: Fri, 01 Jan 1990 00:00:00 GMT
Cache-Control: no-cache
Content-Length: 58
Server: Development/2.0
Date: Wed, 06 Dec 2017 01:33:30 GMT

Browser’s cookies section

Other thoughts & posts explored:

• Tried using both Safari and Chrome, and received the same result in both. I have also verified that cookies are allowed by the browser.
• $http doesn't send cookie in Requests
• Cookie is not set in browser
• How do I SET a Cookie (header) with XMLHttpRequest in JavaScript?

Question:

How do I get the cookies to be saved by the browser so that it can be used in the current session?