[GAMEPLAY] Lux E bug - Uncstable

Hello everyone, I've never posted here so apologies if I make any mistake. I just finished a game playing as Star Guardian Lux, on the top right side team if it matters.

I've leveled up and increased my E spell to level 3, and it became uncastable.

When I looked at the mana cost it claimed it costs 0 mana and I could not cast it despite having full mana. Putting more points into the spell did not fix it.

That is all I have to say, the game was horrendous and I hope it'll be fixed soon or that Lux will be disabled.