Jhin W mark or snare

Hello there! This is just a short post on a bug i found. In a game of jhin, the enemy champion was marked with my w so that it could snare them. I hit my w, but it didnt snare. As well the mark remained on the same target, not sure how long it remained but it happened near the end of the game so i didnt really pay much attention. I'm not sure if it's something wrong with the mark or its something wrong with the snare in general.

Thank you for hearing me out