Unique Strongbox "Empyrean Apparatus" does not work

What should it do?
- It is supposed to contain 3 unique maps
What does it do?
- It contains zero unique maps.
Sample size:
5-6 opened in patch 3.27
Scarabs used:
- One of each ambush scarab (Containment strat)
Maps run:
- Exclusively T17 Fortress, deli orbed, currency chisels, more currency mod rolled

Which Loot Filter(s) have you been using in Patch 3.27?

Of course I have made sure to double check it, both with Filterblade semi-strict and with no item filter at all.

Have not seen that strongbox name myself, but digging around Reddit and other bug reports, I'm guessing there is either some specific condition to cause this bug, or it broke in some patch at least 4 years ago, but is so uncommon that it doesn't get noticed often (or the people getting them don't read the strongbox before clicking it and moves on when nothing on filter). And back then there were no T17 maps, so whatever the bug is potentially predates T17's and atlas tree.

Bit late now, but including a bug report number at the time would include a snapshot for GGG to compare with if they do investigate it. In case it's not the strongbox bugged, maybe it's a specific scarab, monster pack in the strongbox, or atlas passive breaking it? Can't think of anything specific off the top of my head, and the 4-year old Reddit post I'm referencing was just adding strongboxes, no containment. But if there is someone else is getting unique maps from it this league, then there should be some kind of disconnect between the two maps ran.

no screenshot, no bug ref number.....