`loading` subroute in conjunction with equilevel `index` route produce incorrect entries in the browser history

Checkout this routes structure:

When I navigate from the root app route down to Project down to Store, then back up to Project and finally find myself on the app route again, I would expect this full path reflected in the browser history. However, this is what I see there:

Here's how the picture starts looking different (and correct) when I delete the `loading.hbs` subroute highlighted green in the first screenshot:

I can also confirm that deleting the `index` subroute (without touching the `loading` one) also produces the correct history:

So to conclude, having both `index` and `loading` subroutes make the framework generate incorrect entries in the browser history while removing either of them makes things look correct. [Here's](https://github.com/azhiv/ember-page-title-repro) the reproduction repo.