[GAMEPLAY] Viktor's R disappear if he dies

When Viktor casts his ult and dies after it, his ult will disappear after the next instance of damage it does. For example, if he casts his ult and he immediately dies, the ult will do one tick of damage and then disappear without doing the other 2 ticks.

1. Ult with Viktor;
2. Die with Viktor while the ult is still active;
3. His ult will do a last tick of damage before disappearing instantly.

This bug is present since 2 months, could a Riot employee confirm they are trying to fix it since it's happening in Pro-play too?