Problem with Stats in 1.12.2

[XiNaru]

Hello, first of all, I hope this is about this mod:
https://www.curseforge.com/minecraft/mc-mods/chickens

the problem: I use them on 1.12.2 and have a red chicken and a sand chicken, from which redstone chickens should become.
as far as it goes, but I have run it all night, and it has created no egg that about 1 1 1 would come from the stats.