1. make an iron farm that is intendet to work in 1.16 on a 1.14 world
2. swich to 1.16
3. make the same farm in a new 1.16 world

you will see that in the new 1.16 world the farm works but not in the old 1.14 despite the same design

both iron farms should work no matter the edition the world was made in.