I made a superflat world (1 layer of air, and nothing else), and shot a bow.
Then my arrow seemed to hit an invisible wall. No there were no barrier blocks, I wasn't at the world border, and this would happen anywhere. Also I noticed that after about a second, the arrows would reappear, falling into the void, where they should be. This suggests that this is a graphical glitch, so it's not that important, but it is pretty annoying. Also, I didn't have any resource packs on.