This is the screen I got initially with the RT-AX86U with UPNP enabled, under the 386 line of firmware:https://www.grc.com/su/UPnP-Exposed.htm Now it's the "DID NOT RESPOND" page. So Asus must have closed any holes with the more recent firmwares.Earlier I enabled UPnP on my AX86U with latest stock firmware and tested with Shields Up which reported "THE EQUIPMENT AT THE TARGET IP ADDRESS DID NOT RESPOND TO OUR UPnP PROBES!" I normally keep UPnP turned off out of an abundance of caution.