I keep throwing bread to different villagers. I built a large house with 4 beds in it (2 bunk beds now, they were separated before). There are 5 villagers, 2 of them working too far from gathering point, each one with their home and 2 extra beds aside of the 4 new beds I installed in the house I built.

They show hearts when at gathering point, many, many hearts, but then they always end up getting angry and not breeding. There's nothing obstructing the beds (a villager walked in and slept in one of the beds). I keep throwing them bread, they keep trying to mate, but always end up getting angry and just walking off.