Kha'Zix wings disappear??

So, I don't really know much about this, I leveled up my E with Kha'zix when playing and like after a while, it wings disappeared, like i noticed it after dragon and baron buff, and I don't know but like when I tried to jump, like this happened 4 times in the game, like it didn't jump to the fullest while like in my opinion, kha flew its original E but when I tested it after the cd, it stretches back to the evolved E, feels kind of weird, should change it. I was streaming the game and screen shots doesn't seem to work with my keyboard, it goes all black, so you can view that if you want. At 22:02 minutes, lulu W me and after I exit, my wings were gone.