Zed Death Mark bug

Problem: Death Mark not being removed after qss'ing within 3 second how i found said bug was i was playing a team builder game where i was panth top and the enemy zed roamed top 5 times , zed death mark active on me and i used my qss 1 second after but the weird thing was the death mark was still there and this happened 5 times and after i had used my qss