Derelict Mansion boss not starting the fight

Bug Report ID: #3281729895

I'm in the Derelect Mansion boss arena. One of them is dancing around, the other is playing the piano, but we don't seem to be able to engage in combat. It's all rather peaceful, which would be great if I wasn't trying to get my fifth and sixth Map Boss Skill Points from these Deadly Map Bosses (which I assume is an Anomaly boss, it's not very clear).

Potentially relevant details:
Map rolled ritual and breach (breach was on the upper floor of the estate, ritual had 2 above 2 below)
Map had an additional Incubator Queen (very near to boss arena)
Map had a rogue exile (on the upper floor)
Abyss was near to boss room
I have minions
2 monsters remain (I assume that it's our two bosses)
I took a short stroll to the well of souls and back, and relogged, it's still the case
I even tried relogging inside the arena

same bug for me

+1

+1

The first time I've attempted this map the doors didn't open

Found another node later and attempted again, now bosses are stuck dancing.

+1
Bug Report ID: #3113355410

Map rolled Ritual and Deli

+1 Same here.
Multi Tower setup with quant, juiced map. Bossfight doesn't start. That sucks big time.

Same here,no idea how to fix it, a shame...
also got ritual deli on the map.

+1

+1 same issue breach and expedition tier 15

bumping as I foolishly tried this map again and got the exact same result