Jhin W Mark not fading [Gameplay]

Throughout several games, there is a lot of the time when an enemy has the mark from the Jhin W on them at all times, and it only fades with death. It's sometimes quite difficult to tell if they will be snared or not by the W. I'm not really sure what causes this, but it has happened atleast 5 times to me and I wanted to make Riot aware of it.