The firewall rule defined in step 6 is IMHO too strict.
HomeKit hubs (like HomePod, AppleTV) need to be able to talk back to your untagged network.
Alternative suggestions are discussed here, too:
The firewall rule defined in step 6 is IMHO too strict.
HomeKit hubs (like HomePod, AppleTV) need to be able to talk back to your untagged network.
Alternative suggestions are discussed here, too: