[Gameplay] Dr. Mundo has invisible cleavers on enemy team

I played a match as Dr. Mundo (default skin) and the enemy team told me in all chat that my cleavers were invisible. My teammates were able to see my cleavers. By coincidence I was facing a Dr. Mundo (default skin) the next game and saw that his cleavers were invisible as well. My teammates in the second game could not see his cleavers.