I am also observing this kind of problem. In my case, the instance died but was removed independently of juju. It seems that it's not possible to remove the model now (I waited for 2 hours before giving up).
I am also observing this kind of problem. In my case, the instance died but was removed independently of juju. It seems that it's not possible to remove the model now (I waited for 2 hours before giving up).