Lee Sin bug (been around for a while), (GAMEPLAY):

So when you're kicking someone away with Lee and you have your Q on them so you can connect after R, sometimes it'll travel only half the way, like half of R's kick range and it doesn't matter if there's a wall or anything it happens on any surface/area sometimes, I think it's if you press R at the very same time as Q, but either way there is no excuse for said bug because the idea of the mechanic if to travel to the person with the Q on them and when you kick no matter who you kick it has a set distance because it's counted as a knock-up CC so no one can extend the range with flash or anything as they're kicked. It's really frustrating to get shut-down by someone when you perform a very staple combo with Lee (Q-R-Q) and it bugs out and only travels half the way, so basically you have to make up for another 15 feet and you just get kited unless you flash, but then there goes a huge summoner you have to wait it out. I know you can still kill someone by pressing E as they travel, but no one can expect it to bug it just happens sometimes and you don't always have the energy to press E in the first place. Thanks sorry if it's a little incoherent, I haven't had much sleep.