Ashiok and Defiler

Currently on Arena:

if you have `Ashiok, Wicked Manipulator`, `Laelia, the Blade Reforged` and 2 `Defiler of Flesh`.
Then cast a Black Permanent where you Pay 2 times 2 Life.

Ashiok replaces the pay life with 2 different exile effects, causing `Laelia, the Blade Reforged` to trigger twice.

i don't know if that is a bug on Arena, or if that is wanted, because the Rules Manger refuse to answer my question.

The same might not be true for cumulative Upkeep Cost on MTGO