Boss stuck dancing and fight does not start

Bug Report ID: #2874653195

Hello.
I was running Derelict Mansion map and while clearing the first floor, I got close to the boss area and camera started to zoom out. Shortly after I found the entrance to the boss area at the first floor, but I think you are supposed to go from the second floor.
The bosses are not starting the fight and I cannot engage them. They are playing the piano adn dancing.
I went to the second floor, in case there is an entrance there, but there is not.
Now my map is gone, but I thought you guys want to know this.