Rare items that can randomly drop (like fabled meat/skins/bones or advanced bounds mat) will systematically stop dropping after a certain number of kills, until you go to another realm.
I can confirm after hours of tries that nothing rare will drop after a dozen of kill of enemies that can drop a special resources.
For the first dozen the drop rate is somewhat regular based, afterward, it never drop anymore.
I have some example :
- Hollow Metal will never drop anymore after a certain number of bounds killed until you reload. It's not just rarity, it will never happen again.
- Fabled Harpy drops on regular but rare basis for the first dozen of kills and never afterwards.
It's kind of annoying that you can't farm for special resource without loading very very frequently, I would prefer rarer but constant drop rate.
It could also be a revealing of a deeper problem in the loot code of the game.
I doubt it is intentional but i would prefer a more reliable loot, even if its way rarer.