Probably the difference is that you set size scale of 0.005 on the GUI. Since OBJ is a text-based format, if you change the scale then coordinate values may be longer/shorter (“5” is shorter than “0.005”).
Why did you set scale to 0.005 on the GUI? Normally you should set it to 1.0 (to export in mm), but you can change it if you want to export in meters or inches - but 0.005 does not seem to correspond to any commonly used distance unit.