Delirium Scarab of Neuroses does not spawn bosses correctly

As title. Tested on t11, t12, and t14. Both with and without delirium orbs (60% on each I tried) and natural delirium (did not test benchcrafted Delirium). Full cleared maps. Bosses spawned naturally on maps without delirium orbs, at most saw 1 boss each. No bosses spawned at all on the maps with delirium orbs.

edit: appears to work on some maps but is inconsistent

Doesnt work for me either. Tested it in both deli mirrors and orbs on multiple different maps. Does not consistently spawn bosses and has never spawned both bosses.

finding this out in my testing.

Tried it on the following maps
T16 Dunes - only one kosis spawned
T16 Bone crypt - no bosses spawned
T14 Temple - no bosses spawned
T14 Estuary - both spawned

Delirium Scarab of Neuroses seems to have little bearing on how many bosses spawn in a map. Both of these maps spawned no delirium bosses despite near full clearing both maps, and the problem was persistent in several other maps before I began documenting the issue.

The first two screenshots have the Delusions of Persecution atlas notable allocated, the third does not. In all three maps a delirium orb was used on the map and the scarab was used without any delirium bosses spawning.

No delirium bosses appeared in my map with 20% delirium. Does it need to be from mirror or is this still bugged?

EDIT: Tried 2 times in maps with mirror and got bosses in both, then tried again in map with layer of delirium and I got no bosses.