Hi,
As far as I know, there isn't anything that can disable the left or right touchpad click button without disabling the entire touchpad, so if you don't get better suggestions, make sure you still have time to return or exchange it through your store unless you prefer to just RMA the unit with ASUS.
The touchpad buttons should also work in Windows Safe Mode if you want more confirmation that the problem is hardware-related and try to click on different areas of the right touchpad button to see if something may just be a little off-center.
You shouldn't have any errors in device manager with the ASUS factory image and you may want to try to reset Win10 if you don't mind erasing Windows and starting over if you didn't get the Windows Welcome screen the first time you turned on the unit (which isn't normal if ASUS shipped the unit with Windows preinstalled).
Good luck!