You used the “Export to files” feature with “LPS” coordinate system.
LPS coordinate system is better for compatibility with other software (majority of medical image computing software nowadays assumes STL and OBJ files store LPS coordinates). Slicer uses RAS coordinate system.
If you load a model file with LPS coordinates then you can transform it back to RAS as described here.
Overall, I would suggest to use export feature for creating files for other software (mesh editors, 3D printers, etc.). If you want to save data that you will load into Slicer, you can use File / Save.