IP resolution when mounting SMB shares in docker desktop on Mac

I'm trying to run a container on docker desktop on a mac that uses a SMB network drive. I can mount this drive on the mac with an /etc/auto_smb of

/System/Volumes/Data/mount/media    -fstype=smbfs,soft smb://pgcudahy:password@Pi4.local:/PiMedia

but with a docker-compose.yml of

volumes:
  pi4samba:
    driver_opts:
      type: cifs
      o: "username=pgcudahy,password=password,addr=Pi4.local"
      device: "//Pi4.local/PiMedia"

I get

Error response from daemon: error while mounting volume '/var/lib/docker/volumes/admin_pi4samba/_data': failed to mount local volume: mount //Pi4.local/PiMedia:/var/lib/docker/volumes/admin_pi4samba/_data, data: username=pgcudahy,password=password,addr=172.17.0.1: connection refused

I have no idea why the address 172.17.0.1 is substituted in, as the IP for the network share is 192.168.1.55

There's nothing in /var/log/samba/smbd.log on the network drive about a failed connection which makes me think that the IP is not being resolved correctly.