Angular 编辑表单时的角度值

我无法修补嵌套FormArray中的表单值。请帮我改正错误

组件技术

form: FormGroup;
displayPlan(plans: Plans): void {
      this.plan = plans;
      // Update the data on the form
      this.form.patchValue(
        {
        title: this.plan.title,
      });
      this.form.setControl('days', this.fb.array(this.plan.days || []));
    }

JSON:

component.html（示例）

标题
日期：
发件人：
致：

错误消息：

错误：找不到路径为“天->0->日期”的控件
错误： 找不到路径为“天->0->节点”的控件

仅显示标题，没有任何问题

{
    "title": "string",
    "days": [
      {
        "date": "2020-09-21T09:00:04.206+00:00",
        "nodes": [
          {
            "type": "leg",
            "from": "null",
            "to": "oshiage station",
            "transportMode": "train",
          },
          {
            "type": "activity",
            "category": "food",
            "cost": 200,
          }
        ]
      }
    ]
}

<form [formGroup]="form">
  <label for="title">Title</label>
  <input type="text" formControlName="title" id="titleId" />
  <!-- Day -->
  <div formArrayName="days">
    <div *ngFor="let X of form['controls'].days['controls']; let ix=index">
      <div formGroupName="{{ix}}" class="days">
        <label class="col-md-1 col-form-label" [attr.for]="ix">Date: </label>
        <input type="date" formControlName="date">
        <!-- Node -->
        <div formArrayName="nodes">
          <div *ngFor="let Y of X['controls'].nodes['controls']; let iy=index">
            <div formGroupName="{{iy}}" class="nodes">
              <label class="col-md-2 col-form-label" [attr.for]="iy">From:</label>
              <input type="text" formControlName="from">
              <label class="col-md-2 col-form-label" [attr.for]="iy">To:</label>
              <input type="text" formControlName="to">
              <input type="button" (click)="addTravel(ix)" bubbleTravel="true" value="Add Travel Detail">
            </div>
          </div>
        </div>
      </div>
    </div>
  </div>
</form>