Infinite concoction bug

When using Concoctions with the Waistgate Heavy Belt equipped and two Mana Flasks, only one flask's charges are consumed. The second flask's charges are never consumed, yet the Concoction skill can still be used as if both flasks were functioning normally.

This effectively allows the skill to be used infinitely, as it behaves as though it's consuming charges from the second flask when it isn't.

I have tested this with both Explosive Concoction and Fulminating Concoction, and the issue occurs with both skills.