Mod lead to an abyssal boss not working

On a PC I completed map with the abyss lead to an abyssal boss and found the abyssal monsters in the boss room. killed boss and abyssal monsters but no abyssal boss (dark domain or lightless void) spawned.

it did spawn an incubator queen but that should not count as the abyssal boss since it has its own modifier to spawn them, and they are not an "abyssal boss"