When I called the spring boot service I "manualy" added the cookie. I used the CookieService from ngx-cookie-service.

  getNewKey() {
    this.subs.add(this.clientService.getNewKey().subscribe(key => {
      this.clients = key.clients;
      if (key.cookie) {
        var d: Date = new Date();
        d.setMonth(d.getMonth() + 12);
        this.cookieService.set(key.cookie.name, key.cookie.value, d);
      }
    })
    );
  }