[Help needed] Mobile app upgrade to 1.4

I have migrated my app to meteor 1.4 successfully, it runs in the development env perfectly.

I deployed the server tarball manually, all is good. Browser connects to server, the app is available and working.

The problem is the White Screen Of Death that occurs when I test my apk or xcode project on a device.
I have built the app using meteor build path/to/build --architecture os.linux.x86_64 --server http://myserver.com.

When install the signed apk on a test device, the app boots the launchscreen but hangs there and timesout like it doesn’t find the server… But the server is running and the ROOT_URL is set so I don’t understand the issue.

Could it be because of Hot Code Push ?

How can I debug this efficiently ?

You might want to open an issue on github