In case your router is a consumer grade device that supports providing some kind of public or guest network access (unprivileged internet access (sharing) pre-configurations), such LAN network ports or WLANs may not allow incoming port forwardings. Contrary to what makes sense, the port forwarding may only work to devices on to the “internal” network. (And you would need an additional router to really shield off (firewall) any real internal device from that “internal” (actually publicly accessible) network that gets configured with public port forwardings.)