double artifact drop

[jdisk]

Shouldn't artifacts be unique?
I just got the Face of Feat two times in one dungeon.
In the Last Hope Mausoleum it tumbled from a coffin (no monster, just the coffin) and then Celia dropped it.

This was on Lv 30 nightmare,
Tales of Maj'Eyal: Age of Ascendancy 1.2.3
Addons
Escorts Enhanced 1.2.3
Items Vault 1.2.0
Plenum Tooltip: Enhanced actor tooltip display for TOME v2.2a 1.2.1
Stone Wardens Bonus Class 1.2.3
Marson's Bosses Gone AWOL 1.2.2