BeforeLeaveEvent postpone does not cancel url navigation in browser

I am using UI.getCurrent().navigate(route); to navigate to a page. I’ve implemented BeforeLeaveObserver and in the handler I am calling event.postpone(). I find that the page transition is stopped, as expected, however the browser url shows the url for the new target page that should have been canceled. Is this a bug or expected behavior? Thanks

This is known reported issue, you can find more details and follow the development here: