Can't join host to existing cluster

I have a running LXD cluster with four hosts (they are VM’s in the same phisical machine). But when I try to add a new host, I get the following error:

Error: Failed to join cluster: Failed request to add member: Mismatching config for network lxdfan0: different values for keys: volatile.bridge.hwaddr

Any clue?

Sounds the same as Fail to add cluster node with "Mismatching config for network lxdbr0: different values for keys: volatile.bridge.hwaddr" please can you track there.