获取请求不向PHP服务器发送cookie

Question

I am having a weird problem where when I make a fetch request from the client in development it is not sending the cookies to my server (legacy server that does not run on localhost).

Here is my code for the fetch request:

get( url ) {
    return fetch(`${API_URL}${url}`, {
      method: 'GET',
      headers: headers(),
      credentials: 'include'
    }).then( parseResponse );
  },

Headers is a function that returns the following object:

{
    'Accept': 'application/json',
    'Content-Type': 'application/json',
    'mobile': 'false'
  }

Here are the CORS headers I have set on the server (Access-Control-Allow-Origin is dynamic because fetch has issues with *)

Access-Control-Allow-Credentials: true
Access-Control-Allow-Headers: mobile, Content-Type
Access-Control-Allow-Origin: http://localhost:3000

If I print out $_COOKIE I get back an empty array and when I look at the request I get Provisional headers are shown with no cookies.

Any ideas where I messed up?

Thanks In Advance :-)