I have a writeable signal in a service:

private errorEntries: WritableSignal<ErrorEntry[]> = signal<ErrorEntry[]>([])

I have a getter in the service:

  getErrorEntries(): WritableSignal<ErrorEntry[]> {
    return this.errorEntries;
  }

and anode methode:

  public addError(error: any): void {
    const timestamp = new Date().toISOString();
    const message = error.message || error.toString();
    const stack = error.stack || 'No stack trace available';
    const route = this.router.url;

    const errorEntry: ErrorEntry = { timestamp, message, stack, route };
    this.errorEntries.update((entries) => [...entries, errorEntry]);
  }

I have an effect in another component.

  showExclamationMark = false;

  constructor(private globalErrorHandlerService: GlobalErrorHandlerService) {
    effect(() => {
      const errors = this.globalErrorHandlerService.getErrorEntries()();
      this.showExclamationMark = errors.length > 0;
    });
  }

The effect works fine. But the errors.length always empty, why?
I don’t see what I missed.

I noticed during debug in the service one of the errorEntries property
has a value:

  SYMBOL(Signal): 
    value: Array(1)

contains a value.