diff --git a/app/Http/Controllers/Api/ProjectController.php b/app/Http/Controllers/Api/ProjectController.php
index ab670fbf1..7d71d1fd8 100755
--- a/app/Http/Controllers/Api/ProjectController.php
+++ b/app/Http/Controllers/Api/ProjectController.php
@@ -604,13 +604,14 @@ class ProjectController extends AbstractController
                 if (!is_array($item['task'])) continue;
                 $index = 0;
                 foreach ($item['task'] as $task_id) {
-                    ProjectTask::whereId($task_id)->whereProjectId($project->id)->update([
+                    if (ProjectTask::whereId($task_id)->whereProjectId($project->id)->whereCompleteAt(null)->update([
                         'column_id' => $item['id'],
                         'sort' => $index
-                    ]);
-                    ProjectTask::whereParentId($task_id)->whereProjectId($project->id)->update([
-                        'column_id' => $item['id'],
-                    ]);
+                    ])) {
+                        ProjectTask::whereParentId($task_id)->whereProjectId($project->id)->update([
+                            'column_id' => $item['id'],
+                        ]);
+                    }
                     $index++;
                 }
             }
diff --git a/resources/assets/js/pages/manage/components/ProjectList.vue b/resources/assets/js/pages/manage/components/ProjectList.vue
index 6e07c1d86..75d1b3273 100644
--- a/resources/assets/js/pages/manage/components/ProjectList.vue
+++ b/resources/assets/js/pages/manage/components/ProjectList.vue
@@ -623,10 +623,8 @@ export default {
                 column.tasks = this.transforTasks(allTask.filter(task => {
                     return task.column_id == column.id;
                 })).sort((a, b) => {
-                    let at1 = $A.Date(a.complete_at),
-                        at2 = $A.Date(b.complete_at);
-                    if (at1 || at2) {
-                        return at1 - at2;
+                    if (a.complete_at || b.complete_at) {
+                        return $A.Date(a.complete_at) - $A.Date(b.complete_at);
                     }
                     if (a.sort != b.sort) {
                         return a.sort - b.sort;