My reset button is fine. The reset button will just reboot the router. If you wish to clear the NVRAM then you press and hold the WPS button with the power off. Simply power up the router while pressing the WPS button and I hold it in for about 10 seconds just to be safe. The power LED on the router should pulsate very fast while you are pressing and holding the WPS button. That will wipe everything which by the sounds of things would not be such a bad idea for your router. Then manually reenter your configuration setting or use the utility that is attached to a thread in the Asuswrt-Merlin forum. Do NOT use a saved config file to reload your settings as this defeats the purpose of wiping your NVRAM clean in the first place.
Well, my reset button used to reset to factory defaults when held for 5 seconds. But no matter - your method worked fine for doing that. Thanks!