Hello KarenSearle3,
The Asus AC-3200 does not reset like most other routers. The reset button actually boots the router into a "Rescue" mode which is used for the "Firmware restoration utility". According to the manual this is only to be used when your device is pretty much bricked. Say a firmware update gone wrong.
If your just trying to reset the router this has to be done while logged into the router under "Administration" then the "Restore/Save/Upload Setting" tab.
Hope this helps!
-JReiss