I am using the Artifacts mod in my modpack. If you die with an equipped item from this mod, then put another item in the same slot before looting the grave, then during the looting of the mogiga, the previously worn item will be replaced and disappear irrevocably. Can you fix this?

Sorry for my bad english.

It's not that they disappear. They get thrown on the ground when you die, due to Gravestones not having proper trinkets/curios compatibility. If you get to your grave fast enough you can sometimes find the stuff on the ground before it despawns.