Gragas Q/Lux E bug

I watched the report of the Gragas Q bug from Worlds and have experienced the same issue with Lux's E. I believe it happens with abilities that can be re-activated after the initial cast. They end up glitching out and saying "0 mana" for the cost with the ability itself grayed out. The Lux glitch occurred for me in an ARAM after dying during a fight with my E skill still out on the map.

I felt obligated to post on this as it isn't just with Gragas barrel, but also with similar abilities on other champions.

Thank you!