Using:
Forge 1.19.2 43.3.2
chickensmod-1.19.2-1.0.32
jei-1.19.2-forge-11.6.0.1018
scannable-MC1.19.2-forge-1.7.7+dc5ea09

Created a instance with just these mods, and flew all over the nether using the scanner, and found no trace of any of the nether chickens spawning, all the overworld ones are spawning just fine.