Why is Firewall AI at the top of the data usage chart?

If Firewall AI appears at the very top of your Android data usage chart, that does not automatically mean the app itself generated all that traffic. The reason is the way the firewall works technically on Android.

Firewall AI uses Android’s VPN mechanism to monitor and filter traffic locally on the device. Because the traffic of other apps passes through this local firewall channel, Android may attribute that routed traffic to the firewall itself in the system’s data usage view.

That is why the Android chart can be misleading: it often reflects traffic routed through the firewall, not just traffic created by Firewall AI itself. If you want a more accurate picture of which apps are actually communicating, Firewall AI’s own monitoring view is usually more useful than Android’s general data usage chart.

In short: Firewall AI appears at the top because Android attributes traffic routed through the local VPN channel to the firewall — not because the app necessarily generated all that traffic itself.