If you float the icon, then add a clearing div below it to force whatever comes after to be below and not side by side.
By the way, you marked the other thread as answered but It looks like the First parallax piece is still floating and therefore being cut on mobile. may be it is a cache issue and I am not seeing the fix I gave you.
Thanks scrambler, The Facebook icon is perfect now. Not sure what’s wrong with the first parallax piece, but when I view it across devices it looks fine