I think i manage it to work watching the logs, for somereason my game wasn't loading Forge 39.0.9, instead it was running 39.0.6 (still weird that it doesn't work in a 3 older version)
But thank you for the help, im sorry for all of my dumb post
Then, i don't know why my Minecraft Forge doesn't work that way, i have literally the same thing as you (lastest forge and the same world download), but no witches are spawning.
And whenever i try the same world but with NO forge it works
I've used Shulkercraft Witch Farm to try this
http://www.mediafire.com/file/vfiruxw0prcopb6/file or https://www.youtube.com/watch?v=sofyZ44Rw_E&t=350s
(I know it says 1.16, but again i try this world without forge and someone worked
I did what you say, and yes it was 1 witch, i killed her and go up to Y= 190, To see if another witch spawn (I also try to improve spawing plataforms acording to minecraft wiki Swamp hut spawnbox) and no witches are spawing in there
https://imgur.com/a/BpIT3gQ Image 1
https://imgur.com/NRlH9fV Image 2
Witch farms (And i think Swamp huts in general) are broken with Minecraft Forge 39.0.7 and older versions (Minecraft 1.18/1.18.1)
I made one farm in my 6 modded server and didn't work, i started deleting every single mod but still didn't work, so i deleted forge and run a vanilla minecraft 1.18/1.18.1 and... Tadaah!, Witch farm begin to work