As title states, I changed the server config file located in the config folder, after creating a world, the config file is re-wrote back to its original and it moved the one I changed to solcarrot-server-1.toml.bak. I tried moving the edited config file to the world serverconfig folder to fix this issue but it proceeds to do the same thing inside the folder. I again changed the config file and created a new world to test, it did the same thing. This is on 1.21.1 Neoforge, version 1.16.5

If it creates a .bak it likely means the config was corrupt, are you sure the format was correct?

I found the issue, there was a missing comma in the milestone string. Thank you.