Likely an incompatibility with LittleGameplayTweaks which makes bosses have a higher chance to drop their own item. it sometimes interferes with artifact of command dropping their yellow essence, instead dropping their own boss item. Happens rarely, so I'm assuming it's culprit to be the very mod altering those drop rates. Have not tested it without your mod to be fair.
Had bosses_drop_items mod as well obviously. So could be an altercation or indirect incompatibility with three mods. Unsure.
Likely an incompatibility with LittleGameplayTweaks which makes bosses have a higher chance to drop their own item. it sometimes interferes with artifact of command dropping their yellow essence, instead dropping their own boss item. Happens rarely, so I'm assuming it's culprit to be the very mod altering those drop rates. Have not tested it without your mod to be fair. Had bosses_drop_items mod as well obviously. So could be an altercation or indirect incompatibility with three mods. Unsure.
Mod