I have just tried playing some random custom joust matches whilst im expecting a visitor so i dont have to leave halfway through a game, and i was playing oloun. Anhur was part of the 1vs 5 matchup and whenever i ulted him and he knocked me out of my ult with his 2, then i would get the same 'slow' applied to the enemy, but to myself. Anhur seemed to not be slowed anymore, but didnt gain the speed buff from my ult.

I happened on 3 occasions and wasnt sure if others had noticed the same thing? I was impaled against a wall or his pillar when this happened, so havent tested vs when im just impaled and not into a wall