Whenever I save changes to the file, whether in single or multiplayer, the changes are always reverted back to their default settings. Here's the last version of that file I tried to save & use in a fresh single player world, only for it to be overwritten with the default values instantly: https://pastebin.com/YH23D23k
As far as I've seen by using diffchecker & notepad++, there isn't a single comma, bracket, brace, etc. out of place, but I could be wrong... Despite quadruple checking!
TFC version: 1.7.3.161

Check the config, disable this.