Sacrifice a Gem to gain 40% only gives 20 %

Hello,

I used the devine font "Sacrifice a Gem to gain 40% of the gem's total experience stored as a Facetor's Lens" and offered a level 19 gem. It only gives 20 % instead of 40 % (40m)

Item Class: Stackable Currency
Rarity: Currency
Facetor's Lens
--------
Stored Experience: 39.987.584
--------
Adds stored experience to a gem, up to its maximum level
--------
Right click this item then left click a gem to apply it.

Bug#
3.476.809.656