What do you mean with VLAN69_IOT net? An fd00::/8 Matter IPv6 address? And what do you mean with an address assigned by DNS? Did you mean DHCP or RA? There is no such thing as “Matter over WiFi/IPv4)”, because Matter only works over IPv6, However the services over IPv6 can be advertised using IPv4 mDNS or IPv4 DNS. It is not required of a Matter device to support IPv4 though for (m)DNS.