Bosses Not Entering Combat

Bug Report ID: #3753847752

Derelict Mansion bosses not triggering when entering the combat area - Avelyne is doing her idle dance around the area and Varloch is not standing up.

I ran the map as 6-mod, with Overseer, Breach, and Precursor Tablets

Actions taken:
- Moving around the checkpoints does not start the fight, neither does exiting and entering the map.
- Going to character selection and re-entering does not start the fight
- Logging off, logging on, character selection, and re-entering in quick succession does not start the fight.
- Closing the game, logging on, character selection, and re-entering in quick succession does not start the fight.
- Entering the Vaal Ruins, waypointing to hideout, entering the portal into the fight arena does not start the fight.
- Cleared all side content (Rares, Breach, Delirium, Shrine, Strongbox, Essence, Vaal), checkpointed into boss checkpoint, entered the arena does not start the fight.

Tablet Details:

Item Class: Tablet
Rarity: Rare
Legendary Summons
Precursor Tablet
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Item Level: 65
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Adds Irradiated to a Map (implicit)
7 uses remaining (implicit)
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Map has 59% increased Magic Monsters
49% increased Quantity of Waystones found in Map
Map has 73% increased chance to contain Essences
31% increased Gold found in Map
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Can be used in a personal Map Device to add modifiers to a Map.
===============================================================
Item Class: Tablet
Rarity: Rare
Mythic Mandate
Overseer Precursor Tablet
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Item Level: 82
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Empowers the Map Boss of a Map (implicit)
7 uses remaining (implicit)
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Monsters have 9% increased Effectiveness
Map has 34% increased number of Rare Monsters
43% increased Quantity of Waystones found in Map
Map has 39% increased chance to contain a Summoning Circle
--------
Can be used in a personal Map Device to add modifiers to a Map.
===============================================================

Item Class: Tablet
Rarity: Rare
Mythic Inscription
Breach Precursor Tablet
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Item Level: 79
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Adds an Otherworldy Breach to a Map (implicit)
7 uses remaining (implicit)
--------
8% increased Pack Size in Map
Breaches in Map contain 3 additional Clasped Hands
Map has 91% increased chance to contain Strongboxes
Map contains 2 additional Rare Chests
--------
Can be used in a personal Map Device to add modifiers to a Map.