u/JagexLight There's a mechanic in the game that notifies Ironmen that they won't receive loot when they kill an already attacked monster. This only happens when the monster is killed, so it is basically useless. Will this be fixed for group ironman so it notifies you as soon as you attack an ineligible target?
We're working on something to help you spot that much earlier. It's still quite experimental, but we hope to be able to preview it soon. :)