How to debug an App that freezes but only in standalone

Using SDK version 40 in my App here. I’m iOS, I’m getting an error navigating to a screen with a button press, but it only seems to happen in the standalone app.

On iOS devices sometimes it freezes when a button is pressed with a complete and total app lock up. The button just simply calls navigation.navigate to navigate to another screen. Once it freezes, it freezes consistently afterwards. But then again, sometimes it works just fine.

I can never ever ever ever get it to freeze when debugging. It works flawlessly there.

So the bug happens intermittently on the standalone app on iOS with no rhyme or reason. There are no crash logs or exceptions (because bugsnag would be nice enough to tell me). The app just freezes dead.

What’s the best way to flesh this one out?