This might not be the software itself buy maybe related to one of the XML files or maybe a store value in something link config table. The saved advanced criteria appears to create a group but it does so with wrong criteria. Nonetheless the result is not desire or expected.
Since each rule is subtractive, I become confused on how your very last rule can even be applied… as your previous event choices have already filtered out ANY people with a shared event. So the BUT NOT shouldn’t do anything involving shared events (in my way of understanding). EDIT: After a closer look, it appears it should further subtract any folks with non-shared 1900 Censuses, I think. Wonder why it’s defaulting that BUT NOT back to AND for you.
the rule is not really relevant to the issue – the rules are being changed when going form saved criteria to GROUP
the criteria is working correctly. I first tried AND but NOT Exist for that year and that does not work. BUT NOT working in this scenario – I agree the logic is confusing and might be counterintuitive