My Setup (exemplified):

- Pfsense Box version 2.5.0 with Avahi installed and tagged vlan (100) and untaged LAN.

- Omada Controller Software version 4.2.11

- EAP225v3 firmware version 5.0.0 with 2 SSIDs (A, B)

-SSID A is conected to the main untaged LAN

-SSID B is conected to  Vlan 100

-No guest isolation is used

 Multicast (mDNS) is not working properly on my EAP225v3, if i configure my chromecast either on SSID A or B hosts on the same (or different) SSID cannot found the chromecast.

However hosts on my wired lan can see the chromecast no mather what SSID the chromecast is connect to (I have Avahi configured and firewall rules to allow comunication between lan and vlan).

The only way to connect wireless hosts to the chromecast is when I reboot the EAP225v3 and the chromecast, this way the discovery works no matter what is the SSID in wich chromecast is connect to (on both SSIDs multicast discovery is possible because of my pfsense configuration) for a few hours, after that new hosts cannot see the chromecast.

This is very frustrating since I must allow acess to the chromecast across different SSIDs, this setup is deployed on the company that I work on and it's not feasible to restart devices everytime someone needs to use it.

The problem is only with multicast other protocols works fine.

same situation as in this thread:

https://community.tp-link.com/en/business/forum/topic/229292