[GAMEPLAY] Varus - q not working at all

I couldn't use q ability for varus at ALL during the game, linked. I tried switching the hotkey to a instead of q, and it still wouldn't work. I tried clicking on the button on screen, and nothing would happen. No animation, no damage, nothing. It was like I wasn't trying to do anything. When I died, and pushed q, I would get a noise and a message saying I can't use that yet (as I was dead).

While I was also lagging badly during the game, I know it wasn't the lag affecting the q ability as I could still use all my other abilities.

I don't know why this happened. It has been several updates since last I played varus, and have not played him again since. I do not know what steps to recreate the issue.