Zehpyr freezing units (Warwick especially)

Example: I have Zephyr. Unit refuses to walk around tornado. Tornado ends. Unit still refuses to move. Sometimes it is all game. Sometimes it is until a random unit dies. no rhyme or reason. Clear line of sight to another unit as well.

Also, This happens extremely frequently on Warwick. Especially if he ults near the tornado. Warwick bugs himself out with his ult all the time anyways.