Endermen get angry when starred at in creative

While playing in creative mode looking at an Enderman would cause the Enderman's "angry" sound effect but very distorted and dragged out. I have no texurepacks enabled and this isn't the first time it has happened. It happen in 1.12 too. Here is a link to the video of this happening. Link: https://youtu.be/7bnHZZGVOLU