I can see a few related topics, but nothing that covers this specific point. Since setting up my Eero mesh I've lost external access to my Synology DS218j via services like DS Photo. I can access the NAS over WiFi and I have opened the suggested ports via Advanced Settings but it hasn't helped.

DDNS is setup and working and when running the Router Config option is says that the router is not configured for UPnP. I know that Eero does offer UPnP but Synology apparently don't.

Has anyone managed to grant access to things like DS Photo so they can be accessed from outside of the network?