a basic question abot UPnP

[simoncn]

Here is what the documentation for my router (a Zyxel VMG1312-B10A) says about this option:

UPnP

Select Enable to activate UPnP. Be aware that anyone could use a UPnP application to open the web configurator's login screen without entering the Zyxel Device's IP address (although you must still enter the password to access the web configurator).

From this, it appears that this setting controls whether the router itself is discoverable using UPnP rather than enabling or disabling how UPnP discovery works for other devices. I have tried changing this setting and I see the same as you, that it doesn't affect UPnP discovery on my local network.

It is possible that other routers could handle this differently.