[gameplay] Heimerdinger stun does not affect champions ontop of himself

I have played Heimerdinger a bunch and have noticed this many times before but have not been able to report it yet. Whenever a champion uses a gap closer on me and is technically "on top" of me and I throw the stun on them it has no affect. I do not know if this is because it hits my model first but it is pretty gamebreaking, especially when up against champions such as Irelia, Fiora, Leblanc, etc. This basically allows them to kill me negating my cc when it clearly landed directly on them. I wish I had some sort of video or screenshot but alas I don't. If you want to try this out for yourselves just have an enemy champion stand on top of Heimer and have Donger use his stun on them. I will restate that this has happened a numerous amount of times. I have looked at the tooltip and the wiki for his stun and have found nothing saying that the stun will not work if it hits Heimerdinger as well. Thank you for your time.