Rek'sai can't knock up Amumu when Bandage Toss lands.

When playing Rek'sai against an Amumu, if he lands his Q while Rek'sai is underground you are not able to knock him up after the stun duration is over. It does not happen if you move out from underneath him or if he moves out of Rek'sai's hit box. It seems that this bug will happen almost every single time Amumu lands his Q on Rek'sai while you are underground. Items, Skins, Map, etc. does not matter to make this bug happen. The percentage of this bug happening is about 90% of the time. I have recorded two sessions with this happening on Pool Party and Eternal Rek'sai in Summoner's Rift near the Dragon pit. The best way to see this bug is simply by getting a friend or even a bot to play as Amumu (difficulty doesn't matter). I would suggest leading the bot towards river or a place where structures aren't blocking you from knocking Amumu up to test this out accurately. In the links provided are the videos that I mentioned. It might look like I am not rapidly clicking on Amumu but I am clicking as fast as I can, I promise you that. The Eternal skin video with Rek'sai may show how much I am clicking better than the Pool Party Rek'sai skin video. I have them as separate videos mainly because I don't know how to combine two videos together.