Magic and Rare Monsters not spawning from Strongboxes?

I did not see a similar topic, so my apologies if one exists. Bug report 3336283716.

Today I opened two separate regular strongboxes (both in cruel coves if it matters). One had the '3 packs of magic monsters' mod, and the other had the '3 additional rare enemies'. Once opened, there were only white mobs from both boxes.

I suspect this is not as intended as the box said that it was guarded by additional enemies.

I will do some more testing to see if I can verify or if it was just a fluke.

Edit: The two boxes I opened started as white boxes which i rolled into magic boxes that had the +magic monsters and +rare monsters on.

Edit 2: I just opened two rare boxes, one with magic monsters, one with rare monsters and both spawned properly. Will try to roll a white box with +magic or +rare monsters later to match to original scenario.