the update address button is for when you want t change the address manually.
ie, you can insert any value you like. when the value is different to the current Mac Address, then the button will be active
Click the show invisible files button.
Once you find them, remove the . From the beginning of the file name.
Remember to click the hide invisible files button (in FrsktopUtility) once you have renamed them.
@kimedzheeran I don't remember exactly why I utilised an XPC service (its been a while since I looked at the codebase), But I think it was more for privilege escalation. Without it, you would need to enter your password every time to change the Mac address - which is not exactly user friendly.