Uncompletable Ritual in Mirage in Bog Map boss room (Maven casted Up the Stakes also)

Checked everywhere in the boss room and Mirage for the "1 monster remaining". Nowhere to be found. Killed boss, Tukohama, Channel boss, maybe another in the chaos.

Previously completed identical Ritual location and Up The Stakes bosses in the regular map, with no issue.

bug # 3,819,914,567