dnsmasq seems incompatible with set-name: in netplan configuration

Running
ubuntu, Release 20.04.6 LTS (Focal Fossa) 64-bit,
Kernel Linux 5.4.0-181-generic x86_64

With netplan configuration

01-config.yaml
---------------------------------
network:
  version: 2
  ethernets:
    renderer: networkd
    enx180f76faaf68:
      match:
        macaddress: 18:0f:76:fa:af:68
      set-name: LAN
      addresses: [192.168.1.1/24]
      nameservers:
        addresses: [ "127.0.0.0" ]
    enp2s0:
      match:
        macaddress: 04:7d:7b:21:ec:0c
      set-name: WAN
      dhcp4: yes
      dhcp6: no

  wifis:
    renderer: NetworkManager
---------------------------------

and a minimal /etc/dnsmasq.conf

---------------------------------
# Configuration file for dnsmasq.

port=0

interface=LAN
interface=enx180f76faaf68

dhcp-range=192.168.1.2,192.168.1.127,255.255.255.0,12h

log-facility=/var/log/dnsmasq.log
---------------------------------

When starting dnsmasq the logfile tells me:

May 10 22:01:18 dnsmasq[4906]: started, version 2.90 DNS disabled
May 10 22:01:18 dnsmasq[4906]: compile time options: IPv6 GNU-getopt DBus no-UBus i18n IDN DHCP DHCPv6 no-Lua TFTP conntrack ipset no-nftset auth cryptohash DNSSEC loop-detect inotify dumpfile
May 10 22:01:18 dnsmasq[4906]: warning: interface enx180f76faaf68 does not currently exist
May 10 22:01:18 dnsmasq-dhcp[4906]: DHCP, IP range 192.168.1.2 -- 192.168.1.127, lease time 12h

and there is no response to DHCPDISCOVER on enx180f76faaf68.

With
interface=LAN
##interface=enx180f76faaf68

in dnsmasq.config there is no warning that LAN does not exist, but still no response to
DHCPDISCOVER on the LAN interface.

It took me some time to sort this out, but it seems that dnsmasq is not compatible with netplans "set-name: ",
since the original name (enx180f76faaf68) does not currently exist, but the new name LAN is not recognized.

Without "set-name: LAN in 01-config.yaml" dnsmasq finds the interface enx180f76faaf68 and responds to DHCPDISCOVER.

Is this a bug in dnsmasq?

Turned out to be the firewall -- I forgot to change the nic name in nftables, so input from LAN was not accepted.