re: comment #7, the crashdump's juju-status.txt does have hacluster-placement saying 'Insufficient  ..', but the actual units themselves seem fine:

placement/0                                 active    idle   0/lxd/12  10.246.167.188  8778/tcp           Unit is ready
  filebeat/70                               active    idle             10.246.167.188                     Filebeat ready.
  hacluster-placement/2                     active    idle             10.246.167.188                     Unit is ready and clustered
  landscape-client/66                       active    idle             10.246.167.188                     System successfully registered
  logrotated/66                             active    idle             10.246.167.188                     Unit is ready.
  nrpe/79                                   active    idle             10.246.167.188  icmp,5666/tcp      Ready
  placement-mysql-router/2                  active    idle             10.246.167.188                     Unit is ready
  prometheus-grok-exporter/63               active    idle             10.246.167.188  9144/tcp           Unit is ready
  public-policy-routing/42                  active    idle             10.246.167.188                     Unit is ready
  telegraf/70                               active    idle             10.246.167.188  9103/tcp           Monitoring placement/0 (source version/commit 23.01-8-...)
  ubuntu-advantage/67                       active    idle             10.246.167.188                     Attached (esm-apps,esm-infra)
placement/1*                                active    idle   1/lxd/11  10.246.165.31   8778/tcp           Unit is ready
  filebeat/52                               active    idle             10.246.165.31                      Filebeat ready.
  hacluster-placement/1                     active    idle             10.246.165.31                      Unit is ready and clustered
  landscape-client/50                       active    idle             10.246.165.31                      System successfully registered
  logrotated/51                             active    idle             10.246.165.31                      Unit is ready.
  nrpe/67                                   active    idle             10.246.165.31   icmp,5666/tcp      Ready
  placement-mysql-router/1                  active    idle             10.246.165.31                      Unit is ready
  prometheus-grok-exporter/53               active    idle             10.246.165.31   9144/tcp           Unit is ready
  public-policy-routing/32                  active    idle             10.246.165.31                      Unit is ready
  telegraf/51                               active    idle             10.246.165.31   9103/tcp           Monitoring placement/1 (source version/commit 23.01-8-...)
  ubuntu-advantage/56                       active    idle             10.246.165.31                      Attached (esm-apps,esm-infra)
placement/2                                 active    idle   2/lxd/11  10.246.167.191  8778/tcp           Unit is ready
  filebeat/54                               active    idle             10.246.167.191                     Filebeat ready.
  hacluster-placement/0*                    active    idle             10.246.167.191                     Unit is ready and clustered


Thus, I'd say that either the error was in Juju itself, or it hadn't had time to bubble through to the main status.