Mansion in the mist is inacessible

The map where the obelist is supposed to appear does not contain a boss/boss room which causes it to never be openable. I think it's caused by the change they did of removing the boss room when there is no boss but now this makes the mansion in the mist very hard to open unless you happen to have 3 boss around it.

I tried completing the maps around it but it just causes another map next to it to open again with still no modifier on it which makes it impossible to open.

Here a screenshot of my map around it.