I'm not quite sure what you're saying either, because I don't know what the "pot" means. I will just explain the rule. (And personally I think the rules are a little difficult to follow, not to mention that misunderstanding a rule doesn't mean you never read them.)
Let's say you have made a split of an 11 gem card, four of you are playing, so each of you has 2 treasures "in waiting." (The ones you can lose.) And the 3 leftover treasures that couldn't be split are on the gem card.
If you are the only one to leave, you have your "split" 2 treasures, plus you get all leftovers that exist, those extra 3 treasures. So you should get 5 total.
If two of you leave, you each get the already-split 2 treasures, and you get to split the leftovers. Since there's 3 to split, you each get 1 and then there's 1 still left over. (Just like you would do when a gem comes out.) So that's 1 extra for each of you, and you both get 3 treasures total.
If you're saying you're not getting those 3 leftover treasures, that's a bug. But... if you're saying you think you should get the ones that are already out, the 8 total that were originally split, then that's a misunderstanding of the rules. Even if a second matching "bad" card comes out and everyone loses those, no one else ever gets those. You get your share permanently (they're now "safe") and you only pick up the "leftovers" that couldn't be split if you leave. (Plus any artifacts if you're leaving alone.)