FD has a mechanic where killing animals with the knife doubles drops and introduces new food items, however the gauntlet artifact overrides these changes, making it impossible to attain certain foodstuff with it equipped.

Can you check whether this still happens when you manually set a mob on fire and then kill it with a knife while not wearing the gauntlet? The fire gauntlet doesn't modify the loot mobs drop, it only sets them on fire, so it seems more likely to me that this is caused by another mod.

I'll close this issue for now, since it doesn't seem to be related to Artifacts at all. Feel free to open a new issue if you think this is not the case.