Facebook sdk for app installation tracking

I have created an app in developer.facebook.com, followed the implementation steps for FB SDK for Unity. The game is not published yet. I was checking if the installation count shows so that I know it's correctly implemented. So far I have installed in 7 different devices. Other analytics sdk (GameAnalytics) shows 7 installation but the facebook app shows only 1 installation (and the installation time is of the first installation). I am a bit confused here. Anyone knows what's going on with this?