I have been trying to figure out why some of my smart home devices refuse to work with this particular access point when they work on every other one I own. I have some Yeelight smart lights that use modified SSDP (Simple Service Discovery Protocol) which is part of UPnP to my understanding. I use Homebridge (a docker container that communicates with non-homekit certified devices and allows you to control them via Apple homekit). It works perfectly on any other device but in both AP and mutli-SSID modes this device seems to outright block this traffic. I have recorded both the packets sent by homebridge (the "hello out there" packets) in Wireshark as well as the same packets from the smart lights. Homebridge is on the wired connection and the lights are connected to the wifi. I can see both devices' packets on the wired/wifi connections respectively using Wireshark and tcpdump but they do not pass from wifi to wired and vice versa. There is no option to enable UPnP in the device and I have been told it is on the latest firmware. I have also reset to factory and the issue persists. Homebridge immediately finds the lights and communicates with them when I use another acess point but this one does not work in any scenario. As this is functioning as an AP, it should not be blocking multicast or any other packets. The packets in question are basically an announcement to the UDP multicast address 220.127.116.11 on port 1982. This page outlines how this process works and on what protocols, ports, etc: https://www.yeelight.com/download/Yeelight_Inter-Operation_Spec.pdf
Has anyone else had this issue? Thanks in advance!