Villagers Will Not Breed

My friend and I are trying to repopulate a village. We set up a standard breeding area for two villagers, a blacksmith and cartographer. There are 6 beds in the room, with one block spaces between them. I throw 3-4 pieces at each villager, isolating them while doing so to make sure they get the right amount, however after 2 times of doing this, and seeing hearts both times indicating that they had bred, it has been a few days (irl and in game) and neither time has been successful. We have had the exact same model of breeding area in past worlds, but as of right now, we are not able to breed anymore.