No monsters from Breach mechanic

I was playing in a villa ilvl 76 map and i interacted with the breach mechanics that consists of defeating multiple waves of ennemies. Although i fully cleared the area (the one after traversing the grass paart) and made sure there were no walls for the mobs to come, i interacted with the mechanic but no monster spawned for any of the waves even if i encoutnered mobs before cleaning the breach walls.

Bug report 3 187 491 795