[Gameplay] Lissandra's self ult doesn't always make her invulnerable.

When casting ult on yourself more often than not you do not become invulnerable and still take damage. Not an experienced Liss player as I've only played her as she's free this week but the ability description does say your supposed to be invulnerable. At time of ulting no damage over time effects were cast on me. Having seen this multiple times I assume it is a gameplay bug.