1st, let me say that Facebook is having a LOT of technical issues.
Even when I use my PC, click 'nothing happens',
scroll down a bit, and then 'nothing happens', just a white screen below where I am....
this has been going on for me the last several weeks..... things are not happy with the Facebook back end...
FB works for me roughly half the time..... it is not in good health.
and it is doing the same thing with my Note 4.