Testing in Minecraft Java on 2 different smp servers
Environment
Villagers brought from a plains biome into a swamp biome and bred there have babies of both plains and swamp biome. I made a 30 second video showing one of the testing conditions. https://youtu.be/C9QMNf2HLXE In 1.14 full release I tested this and only got babies of the biome of the parents in when they were moved to the swamp biome and bred.
Linked issues
Comments 3
I did check the F3 screen, and all blocks, even the adjacent ones, said swamp biome. I did another test with jungle villagers, using the same parameters, but further into the jungle. about a 30 second video. https://youtu.be/yCEt-R1vOBk
Duplicate of MC-150520
Looks like you're right on the border between a plains biome and a swamp biome. Can you check whether the breeder is completely in the swamp biome? (You can use the biome blend option in the video settings, or the F3 screen for that).