Mobs get stuck in front of fully grown cocoa beans

I have a cocoa bean farm, and when a mob tries to walk past it, it gets stuck in front of the fully grown cocoa bean. The mobs I have seen do this so far are pigs, Llamas, chickens, and cows. My guess is that the mob does not sense the cocoa bean as a solid block, and therefore tries to go through it, but it gets stuck.