Guilfordbeekeepers.org

Ok, I have one hive, two 10 frame deeps, and two mediums. The bottom brood boxes have brood, as they should. The middle medium, nectar that has not been cured and capped, and the top has a rim of nectar and capped honey, and brood from egg to larvae? They also have queen cells in the top medium? This hive wintered in a deep/medium (story and half hive). When I expanded them and added the second deep, I moved the medium up. When I added a second honey super, then I moved the original medium that they wintered in, to the top thinking that they would not usher the queen up that far over new foundation to lay.

(again, I was wrong)

When you split the hive with the new deep, they raised a new queen, thinking the upper medium was now a separate, "queenless" hive. It is likely you now have a 2 queen hive.