There are different kind of presets, and preset prefixed with an "F" is a factory preset. Those presets can't be changed and overwritten. So, you just need to find the factory preset you're looking for and resave that.
so, the preset is definitely overwritten. The effect does nothing at this point. It is an F designated preset and it does not do what it once did.
If anyone can point me to the original parameters, that would be swell 🙂