This is Facebooks newest algorithm. It withholds posts, until the topic is trending, then you will see the input. They do this to keep you looking for newer posts, and possibly posting more, as you do not think anyone is paying attention to you, and your EGO needs feedback. They know how to manipulate (motivate) your usage, and how your time is spent! They want you looking at their ads! So they withhold posts, forcing you to refresh the page, serving you more banners off of your cookies! If you think I am joking, you are seriously WRONG!