It seems that there is some sort of filtering/sorting happening to the icons, which messes up the stacks counter. Whenever the icons (buffs/debuffs) change position/order, the stacks might disappear. A good way to replicate this is to go on a Devourer DH and enable Buffs for Player. You will see Void Meta stacks, but then go in combat and some use abilities, the stacks of Void Meta will disapear at some point. Same for Feast of Souls and Soul Fragments buff. The stacks are visble when the buff is applied, but then vanish at some point.
It seems that there is some sort of filtering/sorting happening to the icons, which messes up the stacks counter. Whenever the icons (buffs/debuffs) change position/order, the stacks might disappear. A good way to replicate this is to go on a Devourer DH and enable Buffs for Player. You will see Void Meta stacks, but then go in combat and some use abilities, the stacks of Void Meta will disapear at some point. Same for Feast of Souls and Soul Fragments buff. The stacks are visble when the buff is applied, but then vanish at some point.