lxd 3.22 networking breaks in el8.2 - lxdbr0 fails

[resdigita]

After Updating a perfectly working machine with CentOS 8.2 and lxd 3.21 to version lxd 3.22 networking is failing. The Bridge (lxdbr1) is starting but gets no IP address. So the containers don't get an IP as well.

In /var/log/lxd/lxd.log I found:

t=2020-07-20T22:42:23+0200 lvl=info msg="Updating the LXD global schema. Backup made as \"global.bak\"" 
t=2020-07-20T22:42:23+0200 lvl=eror msg="Firewall nftables unable to parse existing ruleset: invalid character '^' looking for beginning of value" 
t=2020-07-20T22:42:23+0200 lvl=info msg="Firewall loaded driver \"nftables\"" 
t=2020-07-20T22:42:23+0200 lvl=info msg="Initializing storage pools" 

I could reproduce the issue on a second machine.

On the second machine I use libvirt in parallel. Using libvirts virbr0 as parent in the container configuration, I got an IP connection for every container and everything is working fine with version lxd 3.22

I've checked the firewall tables and could not find anything noticeable.