Bug [GAMEPLAY] Varus's Arrow

Was playing Legend of the Poro King this evening and after a few minutes of clutchness with Varus's Q, it ceased to work. The button icon appeared normal, but acted as if it never came off cool-down, presenting the "You can't use that ability right now" message with repeated attempts. Fun adjusting my build on the fly, though, but it robs Varus of his key mechanic.

Happy holidays!