2x Lavianga's Wisdom bug with Waistgate belt

The unique belt "Waistgate" allows one to wear 2 Mana Flasks at once.

The new Lavianga's Wisdom unique mana flask doesn't stack when you equip two of them at once, and only one of them remains active at all time.

There is no wording on the unique that implies that this should'nt work, so I assume that this may be a bug?

Piggy-backing off of this report. Using one Lavianga's Wisdom and another different mana flask (Melting Maelstrom in my case) with the Waistgate belt, it looks like it combines each of the flask's charges (14 total, instead of 7) to the right side where the mana flask normally is, but prevents you from using any/either of those flask charges.

Report reference #2,168,260,574.

Second this. tried to equip 2 of these on amazon for mana/hp recovery but it takes only the stronger one into effect.