Hi, I got the same problem…
And your tip about add the veth interface to docker0 helped me a lot…
that’s happens because the systemd-networkd tries to manage the link…
To fix:
I added a new file: /etc/systemd/network/20-docker-veth.network
with content:
[Match]
Name=veth*
Driver=veth
[Link]
Unmanaged=true
and restarted the systemd-networkd service
sudo systemctl restart systemd-networkd.service
after that a new container with bridge network worked for me!