I have many Angular components; They all have a method with @HostListener And I converted them into web components on @angular/elements and embedded them in some legacy JSP/JSF pages. This approach works very well and many web components are working properly in those legacy pages. But now I find one component is not listening the event for @HostListener. So I tried those: Embedded this component into a simple JSP/JSF page and it works Embedded another component with @HostListener method into this page and it works Try to find big difference between those two components and found nothing Debug the code in complicated JSP/JSF page and found the component is created and initialized. My versions: "@angular/core": "^15.2.9", "@angular/elements": "^15.2.9", A part of my code: @HostListener('window:' + VcapsEventType.onExchangeRateTrigger, ['$event']) handleExchangeRateTrigger(e: CustomEvent) { console.log(" never get here"); } In JSP/JSF side: function openExchangeRateWarn(ProgramId) { var event = new CustomEvent("onExchangeRateTrigger12356", { detail: { currencyCode: "CAD", currencyRate: 0.32, duration: 8000, programId: ProgramId, } }); window.dispatchEvent(event); } Continue reading...