[M_Six]

Do you have a router sitting between your Asus mesh devices and your modem? Or are you letting the Asus handle router duties? I have a Ubiquiti Edgerouter 4 as the gateway to the internet. So it's cable modem => ER4 => TP-Link switch. My Decos are in AP mode with one wired to the switch. The network is flat (no VLANs) with just the 192.168.1.0/24 network. So I'm not sure if the issue with the multicast packets within the Homekit system lies with the Decos or with the ER4. The ER4 has the ability to run an mDNS repeater and an IGMP proxy, but neither of those should be needed on a flat network. And the Decos handle the IGMP traffic (supposedly). The Deco router options are pretty Mickey Mouse, so I'm not sure I want that to be the moat around my castle, so to speak.