If you mean the .map file that gets saved to FeralHeart > media > terrains, this is normal as that is the actual map file created when saving for the first time, it is not an exports file. When you click the export button, it saves your work and then exports the map as a .fhm with any other exported files to FeralHeart > exports. It may just be that when you export, it decides to create duplicate particle files in FeralHeart > media > particles that would show up like this "name_0".