Comment 1 for bug 1820101

'juju restore-backup' is currently broken if the original backup was taken from an HA controller. This is due to a variety of reasons, mostly around the new controller isn't going to be HA, so a few of the restored bits bring up a configuration that says "you should be HA, wait for the other agents."

I have started working through a step-by-step to manually restore a controller, which we hope to incorporate into 'juju restore-backup'. I haven't finished polishing all the steps, but it might give you steps that you could follow.