Hi!
A note here: It looks like you are using LXD but there are many references to LXC 1.0 (for example, lxcbr0 instead of lxdbr0, 2.0.11 is the latest version of LXD/deb in Ubuntu 18.04). Is there a chance that you are using both LXC 1.0 and LXD commands at the same time?