i don't know why you are losing progress.
however i noticed you say you "space out" the objective "have 14 couples dance" to ensure stability. i assume you mean you are trying not to make too many babies too fast.
actually "have x couples dance" can be completed without having to make babies.
just put 1 man in each barracks, then send in 1 woman, wait for them to dance and then pull her out of the room before they have six. then send her in again until they dance again, you can keep doing this to get all the credit. it could take you a half hour to get them all, nut i usually do it, to get it out of the way in 1 sitting