Derelict Mansion - Bosses Will Not Trigger

Hello GGG Support Team,
I have cleared all extra content in the Derelict mansion and there are 15 monsters remaining in the map. I am in the boss area and it appears the boss battle state did not trigger. Avelyne, the Withered Rose is dancing around and Varloch, the Ashen Lord is still playing the organ.

The map has:
"Players are periodically Cursed with Enfeeble"
"Monsters have 260% increased Critical Hit Change
"+29% to Monster Critical Damage Bonus"
"Map Bosses Grant 23% increased Experience"
"21% increased rarity of items dropped by map bosses
"Area contains an additional incubator queen"
"Monsters have 125% increased Freeze buildup"
"Monsters inflict 125% increased flammability magnitude"
"Monsters have 125% increased shock chance"
"31% increased rarity of items found in this area"
"22% increased pack size"
"97% increased Waystones found in area"


I have tried:
-Town portal and return
-Closure and relaunch of the game client
-Moving back and forth between the boss check point and another
-I performed a currency exchange
-I traced the outline of the boss arena
-I placed an artillery ballista in multiple locations to see if it would find a target
-Outlining the boss arena from the second floor
-I believe I have broken/used every interactable item (e.g. bottles/chests)
-Verified I cleared the summoning stone boss

Having same problems: Avelyne, the Withered Rose is dancing around and Varloch, the Ashen Lord is still playing the organ. Nothing happenes 2 mobs left