Realtime download optimization. How to find a leak? : <p>I'm using realtime firebase. The problem is that randomly it the graphic shows a high quantity of download on some period of time. The main question is not how to fix it. The main questions are:
1) What is the system of Download from Firebase? How does it work? What are the principles? and the Second question is 2) How to find a leak? 
One more interesting fact is that app was published 17 of February BUT the highest leak was on 3rd of February that means it was while testing. It is basic chat app with profiles of users. Media is only photos. But each user got only 1 photo and total amount in storage so far is only 20mb. The size of the app is less than 50kb. So I don't understand how it is possible to download such amount of data and WHAT DATA WAS DOW
DOWNLOADED to make 5GB.
Below the graphic for 30 days
<a href="https://i.stack.imgur.com/kwTMY.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/kwTMY.jpg" alt="enter image description here"></a></p>
