The live data will sometimes revert to not transmitting after engine start on my bike, I need to press the button bottom left of the live data screen. It's labeled kinda backwards, so try pushing it and waiting a second or so to see if it works.
Edit: A weak battery in the bike could cause the voltage to drop enough when starting to disconnect the dongle. Try having a charger on it (not a Battery Tender thing) when starting.
I don't know why it won't re-connect while running, it sounds like an issue with the Android devices. The dongle doesn't care if the bike is running or not, it's just the (wire) between the bike and program. I'd contact Buelltooth?.... because it isn't EMP.