Android : Android Studio run on device, black screen

I've been stuck on this for about 24hrs now. I'm on latest Stable Android Studio and have been developing just fine with Git. Recently however, I've had a problem when pushing the apk to the device. I just get a black screen, with an eventual ANR error. The DesktopLauncher of our app works fine, but it seems only 1 in 5 times it will run on the device when running our AndroidLauncher. I've tried changing cable, moving back to older Git Commits, restarting Studio/ADB/restarting PC/phone/etc.

I eventually found (on SO) that some people had problems with the GlobalConfigs for Google Analytics in their AndroidManifest.

I commented it out, and the problem seems to have gone (for people searching for this in future)

<!-- meta-data android:name="com.google.android.gms.analytics.globalConfigResource" android:resource="@xml/global_tracker" / -->

However, we want to use GA. Any ideas as to why this is causing issues?

Many thanks, J