router.navigateByUrl() causes navigation to root and reload, angular 2.4.7

When I use router.navigate() or navigateByUrl(), I get a reload - a call to the root. The Chrome Dev tools console shows

Navigated to http://localhost/

Navigation via links with <a [routerLink]= works correctly.

app

was generated using angular-cli. Components were generated then modified.
has 3 components test1, test11 (a child of test1) and test2
navigating between test11 and test2 works fine via anchor tag links with [routerLink] (declarative)
navigating from test2 to test11 by using (click) event and programmatic (imperative) navigation call

this.router.navigateByUrl('/test1/test11');

environment

   angular-cli: 1.0.0-beta.28.3
   node: 7.5.0
   os: win32 x64
   @angular/common: 2.4.7
   @angular/compiler: 2.4.7
   @angular/core: 2.4.7
   @angular/forms: 2.4.7
   @angular/http: 2.4.7
   @angular/platform-browser: 2.4.7
   @angular/platform-browser-dynamic: 2.4.7
   @angular/router: 3.4.7
   @angular/compiler-cli: 2.4.7

code

Is published to GitHub, published to GitHub

https://github.com/michaelkariv/angular_router_demo

served by ng serve using production environment

serve --host localhost --port 80 --live-reload false  -prod