Cannot complete The Warmongers II when procced in Doedre's Cesspool

Cannot complete The Warmongers II when procced in Doedre's Cesspool

There are no monsters that spawn in the Cesspool, there were no warbands to defeat.
The Cesspool is just a waypoint with 2 short paths that lead to other areas, hopefully a mistake that prophecies can proc here.

Got same, killed 4 of them but still active and cant be completed...

Same here, no monster left in the area. Checked both connected area, prophecy is not active.