POSTとページ更新を同時に行う

モーダル内の情報をデータとしてPOSTした際に同時にページ更新を行おうと思ったのですが，更新のみが実行されてデータの送信を行うことができませんでした。これではできないのでしょうか？何か解決策がありましたら教えていただきたいです。

JavaScript
1function editTaskParameters(task_id, data){
2  data = 'jsonstring=' + data;
3
4  console.log(data);
5  var url = "https://us-central1-singletasker-dev.cloudfunctions.net/task?api_token=" + api_token + "&task_id=" + task_id;
6  const request = new XMLHttpRequest();
7  request.open("POST", url);
8  request.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
9  request.addEventListener("load", (event) => {
10    if (event.target.status !== 200) {
11      console.log(`${event.target.status}: ${event.target.statusText}`);
12      location.replace(location.href);
13      return;
14    }
15  });
16  request.addEventListener("error", () => {
17    console.error("Network Error");
18  });
19  request.send( data );
20}
21
22function editTask(){
23    var name = document.getElementById('editName').value;
24    var memo = document.getElementById('editMemo').value;
25    var due = document.getElementById('editDue').value;
26    due = due.replace(new RegExp("/", 'g'), '-')
27    var priority = document.getElementById('editPriority').value;
28    // var tags = document.getElementById('tags').value;
29    var hour = document.getElementById('editHour').value;
30    var minute = document.getElementById('editMinute').value;
31
32    console.log(document.getElementById('editPriority'));
33
34    most_important_taskid = localStorage.getItem('most_important_taskid');
35    most_important_task = JSON.parse(localStorage.getItem(most_important_taskid));
36
37    var data = "{";
38
39    if(name != most_important_task.name){
40        data += "\"name\":\"" + name + "\",";
41    }
42    if(memo != most_important_task.description){
43        data += "\"description\":\"" + memo + "\",";
44    }
45    if(priority != most_important_task.priority){
46        data += "\"priority\":" + priority + ",";
47    }
48    if(due != most_important_task.due.replace(new RegExp("-", 'g'), '/')){
49        data += "\"due\":\"" + due + "\",";
50    }
51    if(hour != reformat_time(most_important_task.estimate)[0] || minute != reformat_time(most_important_task.estimate)[1]){
52        hour = ('0' + hour).slice(-2);
53        minute = ('0' + minute).slice(-2);
54        data += "\"estimate\":\"" + hour + ":" + minute + ":00\","
55    }
56
57    data = data.slice(0, -1) + "}";
58
59    most_important_taskid = localStorage.getItem('most_important_taskid');
60    editTaskParameters(most_important_taskid, data);
61
62    // console.log(name);
63    // console.log(memo);
64    // console.log(due);
65    // console.log(priority);
66    // console.log(hour);
67    // console.log(minute);
68    // console.log(data);
69}

HTML
1　　<div class="modal fade bd-example-modal-lg" id="taskmodModal" tabindex="-1" role="dialog" aria-labelledby="taskmodModalLabel"
2         aria-hidden="true">
3        <div class="modal-dialog modal-lg" role="document">
4            <div class="modal-content">
5                <div class="modal-header">
6                    <h5 class="modal-title" id="taskmodModalLabel">タスク変更</h5>
7                    <button type="button" class="close" data-dismiss="modal" aria-label="Close">
8                        <span aria-hidden="true">&times;</span>
9                    </button>
10                </div>
11                <div class="modal-body mx-5">
12                    <form>
13                        <!-- タスク名の設定 -->
14                        <div class="form-group">
15                            <input type="text" class="form-control" id="editName">
16                        </div>
17
18                        <!-- その他パラメータの設定 -->
19                    </form>
20                </div>
21                <div class="modal-footer">
22                    <button type="button" class="btn btn-secondary" data-dismiss="modal" style="border-radius: 100px;">
23                        キャンセル
24                    </button>
25                    <button type="button" onclick="editTask()" class="btn btn-primary" style="border-radius: 100px;">&nbsp;&emsp;変更&emsp;&nbsp;</button>
26                    <!--<button onclick="addTask()" href="home.html" type="submit"-->
27                    <!--class="btn btn-primary btn-lg" style="border-radius: 10px;">作成-->
28                    <!--</button>-->
29                </div>
30            </div>
31        </div>
32    </div>