Android : Why some links shared in facebook open in its internal browser?

I have an app, which shares content in facebook, using the OG data. the og contains also the

al:android:url
al:android:package
al:android:app_name

The problem is the sometimes the links are opened in app, and sometimes in its internal browser. When it opens the link in its internal browser it won't lead the user to the app (obviously). Something really weird is that me and my partner are having the issue alternatevely. I explain it better: If it works for me, it doesn't work for him, If it works for him, it doesn't work for me. What is going on?