A Possible Camille Bug
I was playing Blood Moon as classic Kha'Zix. Whenever the enemy Camille would ult an ally (NOT ULTING ME), I would not get knocked back by her ult.
I'm currently checking the match replay to see if I was in Evolved R or not.
Update: I was in Evolved R, but I wasn't stealthed, but my ult still had a 2nd stealth cast remaining.