Rare monster icon on mini map was remove or turn off it just a bug?

Rare monster was one of the source of loot, after the update, its icon on the mini map is gone, now not only do you need to find the boss room which doesn't appear on the mini map unless you kill all the rare monsters, but you also need to find and kill all the rare monsters if you want to get a lot of good loot while there is no rare monster icon on mini map. Its like back to the beginning