I tried to build a villager breeder in my minecraft aternos server, in 1.15.1 version, and it doesn´t work.
(The breeder is way up in the sky, y=150)
Even though the villager can reach the beds and all that, when the heart particles appear like they were breeding, after a while instead of appear a baby villager it appears angry villager particles and no baby.
It isn´t the first time doesn´t work for me I had already tried in other aternos survival worlds and it doesn´t work. This model works on creative world but it doesn´t in my aternos survival world. (Sorry for my bad english it isn´t my native language.)