On the snapshot (Loving it btw, really fun additions) I was checking out an underwater temple and was followed by a skeleton. The skeleton shot at me and missed a few time, those arrows that missed landed on the temple and in the sea floor and are now making a constant noise as if its hitting something but I'm pretty sure they are just stuck.

I turned the game off and on to check if this would de-spawn the arrows but they are still stuck in the same place and still making the noise.