Auto attacks making sound but do not land

So I have encountered this many times with Shaco and Kennen my two mains.

Shaco : After Deceive (q) the hit makes the sound of the autoattack but it doesn't land. However shaco breaks the stealth, appears and ...dies.

Kennen : Usually with his W enhanced autoattack.. it makes the relative sound it even shows the attack landing and it doesn't land. Also with Kennen the W active sometimes goes on cooldown makes the noise, but it doesn't land if the target goes out of range. These are quite often bugs and are really annoying.