Strongbox bug T17 Fortress

The Strongbox opens, I kill the creatures inside, and the box does not drop the last loot it should drop. Instead, it says "This Chest Locked" and this is valid for all 20 or so boxes in the map.
I think it's because of the atlas tree, the scarab that can be re-opened or something like that. I experience this problem occasionally in other T17s, some of them happen like this, but this is the first time I came across in Fortress that not all boxes were opened.


Edit: I think searing exarch ground mod thing causes the problem.

Experienced this twice as well.

Both of the maps had the searing exarch runes modifier on them.

I've met the same problem with strongboxes if exarch runes or elder rings mods are rolled.

I've met same problem :(

Ive also encountered this multiple times.

Same exact issue on Ziggurat, also with Searing Exarch rune mod.

I have also experienced this. The map also had the modifier "Area contains Runes of the Searing Exarch".