So i first noticed it when i was playing Janna and i threw a tornado at a Nidalee and she pounced over it without getting knocked up. At first i thought it was just a one time minor bug but then i started noticing it alot more. I am not too sure if this is a common occurrence or a rare one but it has happened when i played Lee and my q went through the target . A while back i also reported the Ashe ult bug where it phased through the enemy twitch. So i am not sure what causes it or , again, if its common or rare but i just thought it should be looked into or see if anyone else is noticing it too.
Unfortunately no video/screenshot.