That is kind of the same as my problem, which I explained here. From what I understand, the back button only appears when a view gets replaced. For example, the state ‘tabs.facts1’ uses the ‘home-tab’ view, and when it gets replaced by ‘tabs.facts2’ using the same view, the back button appears. From what you’ve changed the view that gets replaced is not ‘home-tab’ anymore but the default one (the one without a name).
That’s from what I’ve understood so far, so don’t take my word on it. I can only say that from what I’ve experienced that is not always the case. Here is hoping someone can clarify on this matter.