Access Point mode issue, airplay not working.

[ali.]

I've been having some issues with my Asus Ai-Mesh setup in access point mode. For some reason, AirPlay isn't working. I tried switching to router mode and found a setting called "enable multicast routing" which seemed to briefly fix the issue with AirPlay. However, I'm unsure if I set up the router mode correctly, as I have PfSense as my main router.

Can anyone help me with the router mode settings? What settings do I need to turn off in router mode so I do no have double NAT, and should the incoming connection from PfSense be directed to the WAN or LAN port?

Thanks in advance.