Everytime I make edits to the json file, it reverts back to the original file. Not sure if I'm doing it wrong or what.

If a configuration file resets, it generally means that the file was not valid JSON so the file was reset to defaults. When making manual edits, please make sure to follow JSON standards and validate using a site such as http://www.jsonlint.com if you need help a hint.

I think it's because I'm running Dynamic PVP and Zone Manager, and one of them is constantly overriding TruePVP. Sorry I forgot to mention that in the first place.