Stygian Spires in Delve and Abyssal Depths don't do anything anymore

I've noticed that Stygian Spires in these 2 encounter types... don't do anything as of this league.

They used to shoot mortars into the air as you reduced their HP, and these would spawn abyssal cracks that spawned monsters.

Now the spire just sits there waiting for you to DPS it until it crumbles. No mortars, no monster spawns, no nothing.