Angular ActivatedRoute data returns an empty object

Edit: the problem is that I was trying to access the ActivatedRoute from a Component which is outside the <router-outlet>. So it looks like that this is the intended behaviour.

However I still think that my answer below can be useful to anyone who is trying to accomplish the same thing.

import { Component, OnInit } from '@angular/core';
import { Router, RoutesRecognized } from '@angular/router';

@Component({...})
export class MyComponent implements OnInit {
  private routeData;

  constructor(private router: Router) { }

  ngOnInit() {
    this.router.events.subscribe((data) => {
      if (data instanceof RoutesRecognized) {
        this.routeData = data.state.root.firstChild.data;
      }
    });
  }
}

doing this way this.routeData will hold the route data that I needed (in my case the page title).

Get route custom data for component outside <router-outlet> (Angular 8):

constructor(private router: Router) {}
    
ngOnInit() {
    this.router.events.subscribe(data => {
      if (data instanceof ActivationStart) {
        console.log(`Custom data`, data.snapshot.data);
      }
    });
  }