Curse of Strahd: Are Dark Powers from Shadowfell or from Amber Temple?

I am running the Curse of Strahd and one thing seems inconsistent. In chapter one it says

Unwilling to go the way of his father, Strahd studied magic and forged a pact with the Dark Powers of the Shadowfell in return for the promise of immortality.

However, in the chapter thirteen the story is different:

He knows only that the Dark Powers that created Strahd’s domain were born in the temple, and that these entities feed on the evil that Strahd represents.

How does one reconcile these two things?

Have the powers originate in the Amber Temple, but later moved to Shadowfell? Are Dark Powers different from what evil vestiges that the Amber Temple also mentions (and some point switches from evil vestiges to Dark Powers)?

Finally, how can it say that Dark Powers originated in the Amber Temple, if the evil vestigates are:

They needed a vault in which to contain the evil vestiges (rem­nants of dead, malevolent entities) they had captured and the hoard of forbidden knowledge they had amassed.

So the malevolent entities must have existed before the Amber Temple. Were these the Dark Powers?