Derelict Mansion boss not starting.

Bug Report ID: #1320329380

Just tried to complete a derelict map but the boss didn't want to engage with me. After moving around a bit, only the guy playing on the piano started attacking me but the dancing lady is still not interactible

Map that I used to run derelict had delirium on it.

Same for me actually. She's just dancing around the courtyard and singing. The piano bro is just sitting there playing his thing.
Delirium on it as well not sure if that matters.

https://imgur.com/a/8vJzDXi

Just happened to me as well.