Abyss not spawning

The game can't open the abyss because it still expects some abyss monsters to be killed. I had this bug multiple times recently on different maps (I don't remember them), current map is "Sinkhole". There is nothing to open nearby, and no stationary mobs to kill anywhere.

This might be nothing, so take it with a grain of salt, but one thing I would add to this is that I killed these abyss monsters with the "chaos explosion shrine" active, and I only got this bug since recently around the time I specced into the shrine nodes on the atlas tree.

Another thing I saw was that there was still a lingering "abyssish" effect on the ground, as if there was a monster underneath.