blushthen I believe the answer is right there in front of you where it says:
"Tracking usage not yet supported"
So no GrapheneOS user will see anything there. If I remember correctly, it's always been this way. Not sure what the point would be for the developers to add support because in order to do that they'd have to support yet another feature. If you want to track which apps are accessing the network, you can try using an app like Rethink DNS.