Why is jquery's .ajax() method not sending my session cookie?

Question

After logging in via $.ajax() to a site, I am trying to send a second $.ajax() request to that site - but when I check the headers sent using FireB

Answer 1

After trying out the other solutions and still not getting it to work, I found out what the problem was in my case. I changed contentType from "application/json" to "text/plain".

$.ajax(fullUrl, {
    type: "GET",
    contentType: "text/plain",
    xhrFields: {
         withCredentials: true
    },
    crossDomain: true
});