Don’t know what you mean @CarlosLU?

Are you saying you just enabled UPnP (auto-port forwarding) in your router configuration? - If so, that’s for opening/closing ‘external’ ports on the fly rather than using manual port forwarding - I can’t see how that might have any relevance to device discovery when ALL are on the local network subnet anyway - You perhaps need to provide some additional detail, maybe with screenshots, which may assist with understanding of what you changed in your router settings.

Just to add, I had to enable UPnP on my router to get Sonos working with the in-built Plex service (as that required remote access to be enabled). It uses NAT loopback to make the Plex service discoverable - I’m not sure why Sonos/Plex do that other than perhaps it’s a check that a Plex pass is associated to the account, but in my case, it will not work with my chosen router unless I enable UPnP (that’s even with internal TCP port 32400 manually forwarded)  - but clearly that’s not anything to do with the actual discovery of Sonos devices which work fine in my case with UPnP set as disabled.
 

That said, I have seen Sonos Staff in the past suggest UPnP be enabled on a router whilst some users tend to see it as a bit of security risk and so leave it disabled.