Angelic Buster's "Power Transfer" skill displays wildly inaccurate remaining duration

Every time you recharge your Soul Battery skills, the duration on Power Transfer will appear to refresh.
It isn't actually refreshing and will eventually just vanish, even if it's still showing itself as maxed out.

Like any other skill with stacks.

Power Transfer, afaik, doesn't stack. The skill only states it's a simple damage reduction.

I thought the damage reductions stack?

Doesn't say anything to that effect in the skill's description, anyway.
So maybe in addition to the obvious bug, they're completely forgetting to let us know it has some sorta stacking mechanism? :v