Looting Corpse too fast causes it to disappear
 

My corpse had just disappeared when I was spam rightclicking arrows on my corpse. I lost stacks of items two bags.

The corpse would not have disappeared unless you looted all the items. If you were looting too fast the game will kick your off the corpse, in which case it is still there.

Do you have /hidecorpse all or /hidecorpse looted on ?