HarmonyOS 间接使用自定义Dialog，controller属性undefined问题

//Index.ets
import { MyDialog } from './MyDialog'
import { TitleButton } from './TitleButton'
@Entry
@Component
struct MyPage {
  build() {
    Column(){
      TitleButton({
        title:'OpenMyDialog',
        customDialogController: new CustomDialogController({
          builder:MyDialog()
        })
      })
    }
  }
}
//MyDialog.ets
@Component
@CustomDialog
export struct MyDialog {
  controller: CustomDialogController;
  build() {
    Button('Quit')
      .onClick(()=>{
        this.controller?.close()
      })
  }
}
//TitleButton.ets
@Component
export struct TitleButton{
  @Prop title:string;
  customDialogController?: CustomDialogController;
  build() {
    Column(){
      Button(this.title)
        .onClick(()=>{
          this.customDialogController?.open()
        })

    }
  }
}

Demo代码文件上面给出,这个场景是 MyPage => TitleButton => MyDialog,我直接在MyPage中new一个CustomDialogController传给TitleButton，builder使用MyDialog，这个demo下，MyDialog弹窗中的Quit按钮是无法退出弹窗的，调试发现MyDialog中的controller为undefined。

若修改Index.ets和TitleButton.ets如下，则Quit按钮正常退出，程序正常运行，请问为什么上面那种不行。

//修改后Index.ets
import { TitleButton } from './TitleButton'
@Entry
@Component
struct MyPage {
  build() {
    Column(){
      TitleButton({
        title:'OpenMyDialog',
      })
    }
  }
}
//修改后TitleButton.ets
import { MyDialog } from './MyDialog';
@Component
export struct TitleButton{
  @Prop title:string;
  customDialogController?: CustomDialogController;
  build() {
    Column(){
      Button(this.title)
        .onClick(()=>{
          this.customDialogController=new CustomDialogController({
            builder:MyDialog()
          })
          this.customDialogController?.open()
        })
    }
  }
}