自定义组件EventEmitter没有观察者

Question

我已经制作了一个自定义组件：

@Component({
    selector: 'comp-rating',
    templateUrl: 'comp-rating.html',
    changeDetection: ChangeDetectionStrategy.OnPush
})
export class CompRatingComponent {

    @Input() public score: number = 1;
    @Input() public max: number = 5;
    @Input() public width: number = 150;
    @Input() public height: number = 138;
    @Input() public prefix: string = '';

    @Output() public update: EventEmitter<number> = new EventEmitter();


    constructor() {
    }

    onUpdate(score: number): void {
        if(score === 0.5) {
            score = 1;
        }
        this.score = score;
        this.update.emit(this.score);
        console.debug(this.update);
    }

    public icons(): string[] {
        let step = 0.5;
        let score = Math.ceil(this.score / step) * step;

        let icons = [];
        for (let i = 1; i <= this.max; i++) {
            if (i <= score) {
                icons.push('<img src="../../assets/images/rating-full.png" usemap="#' + this.prefix + '-' + i + '">');
            } else if (i - step <= score) {
                icons.push('<img src="../../assets/images/rating-half.png" usemap="#' + this.prefix + '-' + i + '">');
            } else {
                icons.push('<img src="../../assets/images/rating-empty.png" usemap="#' + this.prefix + '-' + i + '">');
            }
        }
        return icons;
    }
}

当我单独使用此组件时，效果很好。 但是当我在ngFor上使用它时，EventEmitter找不到Observer ... 我的html：

<ng-container *ngFor="let critere of criterions">
    <ion-list no-lines>
         <comp-rating [prefix]="'critere-' + critere.id_criterion + '-'" [score]="1" [max]="5" [width]="100" [height]="90" (update)="onCritereRatingChange($event)"></comp-rating>
    </ion-list>
</ng-container>

如果有人有ID，如何解决观察者的问题。