Why aren’t my villagers breeding?

I’ve got one villager up 7 blocks surrounded with 6 doors. On ground level I have villagers who are supposed to breed. They are willing, their inventories are full of potatoes, and I’ve been sitting here for hours. Hearts are popping up above their heads but nothing happens. I am playing on Xbox One.

Villagers breeding is directly related to the number of doors in their village (Naturally generated or otherwise) The Villagers will only breed when the number of villagers is below 35% of the number of doors in the village, Supposing you have 6 doors then the villages population cap is 2.1 villagers. Correct me if I'm wrong but I believe you need more doors