加载动画有时消失，有时不消失，脏检测问题

Question

 ngOnInit() {
            this.context = this.tasksService.tasksContext;
            this.params = {...this.context};
            this.form = {q: this.context.q, checkboxes: []};
            this.itemsSelected = this.context.itemsSelected || [];

            this.appsState$ = this.appsService.appsState();
            this.sharedAboutService.getFeatureInfo()
              .subscribe((featureInfo: FeatureInfo) => {
                this.schedulerEnabled = !!featureInfo.schedulerEnabled;
                this.refresh();
              });
          }
          refresh() {
            this.loading = true;
            this.tasksService
              .getDefinitions(this.params).pipe(map((page: Page<TaskDefinition>) => {
              this.form.checkboxes = page.items.map((task) => {
                return this.itemsSelected.indexOf(task.name) > -1;
              });
              return page;
            }))
              .subscribe((page: Page<TaskDefinition>) => {
                  if (page.items.length === 0 && this.params.page > 0) {
                    this.params.page = 0;
                    this.refresh();
                    return;
                  }
                  this.taskDefinitions = page;
                  this.changeCheckboxes();
                  this.updateContext();
                  this.loading = false;
                },
                error => {
                  this.loading = false;
                  this.notificationService.error('错误', error);
                });
          }

加载动画有时消失，有时不消失，脏检测问题？ 我认为这是一个肮脏的测试问题，但我不知道如何解决。 可能还有其他问题。