I'm having this same problem. Been searching for hours for a solution. Setting Facebook app to not open by default in either device or app settings does not work reliably if at all. Opening the link purposely in new tab does take me to Facebook site with no app. Seems like it should be possible to make a link that would do the same thing.

Adding a note for visitors to select ”open in new tab" in the browser is the only solution I can find so far.