When app is put in background and network is disconnected, white screen is displayed without any error

Steps to reproduce :
1) put your app in background
2) open network prefs and disable all networks (as if you were in a tunnel without wifi or phone data network 3G/4G)
3) call your app back -> a white screen is displayed

The main problem is how to debug that as when your disconnect your network, you don't have any more console log information (i'm using expo) nor debugger.
I'm trying to :
- debug within XCode with USB plug, but as there is no error in libraries, unsuccessful for now
- setup a github with meteor testbed and snack.expo.io project to reproduce the problem without my full app

If someone has an idea, we can discuss in the gitter Lobby.