After numerous Diablo 4 dungeon nerfs over the last few days, it appears that the Ruins of Eridu dungeon farm has also been hotfixed!
Elite Spawn Rate Nerfed in Diablo 4 Dungeons More Diablo 4 Dungeon Nerfs
Before the server-side hotfix, players were able to make use of the overhauled “Slay All Enemies” dungeon objective. After some time and a certain amount of monsters killed, additional monsters will spawn on top of a random party member.