Docker Swarm in LXD containers

I am trying to run a swarm cluster inside LXD containers but it keeps failing with the below error message:
** fatal task error" error=“error creating external connectivity network: cannot restrict inter-container communication: please ensure that br_netfilter kernel module is loaded” **
I am running LXD version 3.0.1
my host is an ubuntu 18.x based
docker version is 19.3
Standalone docker containers inside the LXD containers are running fine.
I’ve also checked all needed kernel modules are loaded , including the overlay and br_netfilter
Packages qemu-kvm and libvirt-bin are installed both on the host and in the LXC containers.
WHat I am missing ?