Boss drops with ironman class

I am currently playing a hardcore, hunted and ironman assasin. I've tried to do the Corrupter of the worlds boss with another player as help, but when we defeated him, he didnt drop anything for me. We killed him around 7 times. After I killed him alone, he dropped just fine. The same thing happened with Bob from the Reincarnation quest. Is ther some sort of feature that prevents ironman players from getting boss loot when in group

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Nevermind, Just read the wiki, apparently you have to solo bosses to get the drop
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Boss altars have a static drop rate and is well known to mess up if players do it co-op.

Additionally, ironman players are required to deal at least 95% damage to the mob to get anything from it.