Let me say first that I've researched this for the past 4 hours. From various threads, I have seen that linking to fb://page/PAGEID
is the OLD way of opening the Facebook app via a website link and that fb://facewebmodal/f?href=FACEBOOKURL
is the new way.
As a reference: Open Facebook Page in Facebook App (if installed) on Android
The problem now is, I've tested both of them on iOS and Android today (June 04, 2018) and the one that works is the supposedly old way: fb://page/PAGEID
. Did Facebook change this at some point again? I'm using the absolutely latest version of the Facebook app.
What is the correct way to do this in 2018?