1) Purchase an app in the Stage store. 2) Receive the pin and confirm 3) Receive the payment confirmation and press "Continue" and then "Install" 4) App is installed, and the button changes to "Open" 5) When you press the button, the app does not open. It does open from the homescreen. 6) When you return to the Stage store, the button says "Install", even though it is already installed, and if you press it, you get an error message saying it is already installed. It should say "Open". Reproducible? Yes.
what app are you trying to purchase? Is this on desktop? This bug looks very similar to https://bugzilla.mozilla.org/show_bug.cgi?id=1043965.
All the "Onlyboku..." apps, at least, have this issue, using the Flame. I have most already purchased, and after I re-install them, the button doesn't change to "Open", it remains as "Install", even if you open the details page. It only changes to "Open" right after purchasing, and pressing the button does nothing, it does not open. You can only open it going back to the homescreen. This was the only issue found during today's UAT.
It's worth mentioning that this did work before, I'm not certain how recently, but the installed apps did say Open and they opened when the button was pressed.