Incinerate of venting dmg Bug

The incinerate of Venting gem seems to not apply the damage buff from stage, ie the 25% damage for hits and Ailements per stage, to the damage calculation ingame.

Could you please verify if the damage is being applied. It takes me 12mins to kill the incarnation of dread (lvl 84 with 89 Million HP) which is roughly 120k dps.

That dps fits my stage 0 dps i calculated in excel and matches roughly POBs numbers.

If stages would apply the damage should have been roughly 5x higher.

Thanks for reading!