HarmonyOS 鸿蒙Next WebviewController accessBackward 返回false

使用webview加载远程页面，页面上点击发生跳转，onPageEnd中URL发生变化，但是调用this.controller.accessBackward()，返回false，不能回退。 代码如下:

Stack() {
  Web({ src: this.link, controller: this.controller })
    .onControllerAttached(() => {
      let userAgent = 'Android' + this.controller.getUserAgent()
      this.controller.setCustomUserAgent(userAgent);
    })
    .javaScriptAccess(true)
    .onlineImageAccess(true)
    .mixedMode(MixedMode.All)
    .zoomAccess(true)
    .domStorageAccess(true)
    .overviewModeAccess(true)
    .onPageBegin((event) => {
      if (event) {
        console.log('onPageBegin url:' + event.url)
      }
    })
    .onProgressChange((event) => {
      if (event) {
        console.log('onProgressChange:' + event.newProgress)
      }
    })
    .onPageEnd((event) => {
      if (event) {
        console.log('onPageEnd url:' + event.url)
        this.setBackViewVisibility(event.url)
      }
    })
    .onTitleReceive((event) => {
      if (event) {
        console.log('onTitleReceive title:' + event.title)
      }
    })
    .onResourceLoad((event) => {
      console.log('onResourceLoad: ' + event.url)
    })
  Stack() {
    Row().width(32).height(32).backgroundColor($r('app.color.C2')).borderRadius(50)
    Image($r('app.media.icon_paper_back_new')).width(24).height(24)
  }
  .width(60)
  .height(60)
  .margin({ bottom: 30 })
  .alignContent(Alignment.Center)
  .visibility(this.backViewVisibility)
  .onClick(() => {
    console.log(`clickBack`)
    if (this.controller.accessBackward()) {
      console.log(`accessBackward`);
      this.controller.backward()
    }
  })
}.alignContent(Alignment.BottomStart)