RT-AC86U WPS Clear NVRAM

I just got a RT-AC86U and was trying to clear the NVRAM using the WPS button method like I have been doing on my RT-AC68R, but it isn't working. Only the power light comes on briefly and then turns off and then nothing happens. I've held the WPS button down for as long as a minute. I think it goes into some kind of limp or recovery mode; the WiFi turns off and I get the 169.254 IP and can't access the setup page. Unless I turn it off and turn it back on without pressing any buttons.

I know...

RT-AC86U WPS Clear NVRAM